PUBLIC SERVICE COMPANY OF COLORADO RECORDS
Scope and Contents
The Public Service Company of Colorado (PSCo) Collection contains materials created or used by the company and its predecessor companies from 1869 into 2015 and beyond. A few items predating the 1869 formation of the Denver Gas Company are included, most pertaining to individuals - especially James Archer. The formation of the Denver Gas Company in late 1869 resulted in a flurry of activity the following year as construction began to create a gas line system for the town of Denver. Early invoices from a wide range of companies in Denver and elsewhere are a substantial portion of these early records. Of particular note are the contracts for the delivery of coal with the newest trains serving Denver in 1870 and later. Much of the collection details activities in the early 1900s following the formation of the Denver Gas and Electric Company. Long time employee Roy Munroe (1883-1980) worked in the gas sales and marketing departments beginning in 1900 and kept numerous items which are included in this collection including personal remembrances, notes, photographs, pamphlets and brochures. Many of the materials date from the mid 1950s through the 1996 merger with Southwestern Public Service Company to become New Century Energies and the subsequent merger with Northern States Power Company which in 1999 resulted in the creation of Xcel Energy Inc., headquartered in Minneapolis, Minnesota.
The bulk of this collection stems from the activities of what was first called the Publicity Department, then Public Affairs, and finally Corporate Communications. As such there is heavy emphasis on communication with the employees and the public. Substantial marketing materials are included in this collection as are the brochures for power plants and other company facilities. In addition a great deal of historical information about predecessor companies and the communities in which they provided gas and electric service is included. Franchise election brochures and clippings are well represented, especially for the Denver franchise elections conducted approximately every 20 years beginning in 1906. Information about various subsidiary companies is included too.
Photographs are the heart of this collection. They were donated to the Denver Public Library for safekeeping. Many of the other materials were donated later in order to give context to those photographs, and show how they were used in company publications. Photographs of individuals have been preserved and have been indexed as much as possible although some of the more than 250,000 images remain unidentified.
Marketing methods, referred to as “new business” and “load building,” in the 1910s and 1920s, are well documented, as are the more concentrated efforts at marketing services and goods from the 1960s through the 1990s. Energy conservation melded with environmental concerns beginning in the 1970s, and their emphasis shifted from the "homemaker" type programs that featured recipes, and summer cooking programs for students to a focus on the wise use of energy and effective conservation techniques.
Financial information in the form of statistical comparisons with other communities and companies form part of the collection. Rate case filings are noted, some with summaries of the potential impact, but the actual documents filed with the Public Utilities Commission are not contained in this collection, with the exception of rate case testimony filed in an emergency rate case in 1980. Shareholder reports and communication with employees about the financial condition of the company comprise a portion of the collection, including several ten-year financial summaries. Henry L. Doherty was responsible for much of the growth of the Denver Gas and Electric Company and subsequent company entities including Public Service Company of Colorado. Many references to Denver and his experiences are included in the 1923 compilation of his speeches and writings for the Doherty Men's Fraternity. Doherty arrived in Denver before the turn of the century and became president of the Denver Gas and Electric Company upon the death of George T. Thompson in 1900. He was at the same time president or general manager of nearly a dozen utility companies across the country. Jerome Smiley wrote in his 1901 History of Denver, "While his headquarters are in New York City, and his legal residence in Madison, Wis., he spends much the larger part of his time here in Denver..." Several scrapbooks with extensive collections of newspaper articles are included tracing company activities and those of competitors as well as franchise elections and reports on various individual officers and employees.
The structure of the company is documented in organization charts that date from the 1920s until 2000. Executive speeches and biographical information is contained, as are board affiliations and directorships. Geographical divisions, which existed as administrative segments of the overall operations of the company, are noted within the organization of the company. Yearly fiscal planning documents are also included.
The operating departments of the company are represented by a limited amount of material, typically these consist of the history of a department or power plant written by an individual. Details about the day-to-day operations of the electric, gas and steam departments are lacking with the exception of a few gas operations and utilization manuals from the late 1980s and a few manuals of safe practices.
Histories of the various power plants, particularly the early ones, are well documented with emphasis on their construction progress. Most notable are the two hydroelectric plants constructed early in the 20th century; Boulder Hydro and Shoshone Hydro. Each of these plants, and their water handling systems, were photographed frequently and those photographs are available in the photo series. Progress reports by the Colorado Power Company, which constructed the plants, and numerous documents recounting their construction and operation are contained here too. The Pawnee power plant, near Fort Morgan, is particularly well represented including the environmental and other concerns expressed before construction actually began in 1976.
Of particular note is the extensive documentation of the planning, construction, operation, and ultimate decommissioning of the nuclear generating plant, Fort St. Vrain, located near Platteville, Colorado. The unique high temperature gas-cooled reactor (HTGR), although safer than conventional nuclear reactors, was burdened by its one-of-a-kind design and became the first commercial reactor to be successfully decommissioned in 1997 and received the Edison Electric Award for the company. It was the second time the esteemed honor had been won by PSCo, the first was received in 1968 for the pumped-storage hydroelectric plant, Cabin Creek, near Georgetown. The Leyden Gas Storage Facility in the foothills near Arvada is of particular interest for its unique use of an abandoned coal mine. The mine entrances and air shafts were plugged and the enormous space was filled with pressurized natural gas for use on high demand winter days. The addition of this storage capability made it possible to eliminate the large gas holders that were scattered across the Denver Metropolitan area to provide adequate gas for particularly cold periods. Due to encroachment of residential development on the site the company closed the storage facility about 2002.
The history of the Company and its predecessor companies are included in this short series, as are the companies which resulted from mergers. Periodically the company would produce a history of its activities which were often reworked previous histories updated with the latest activities, acquisitions, and corporate focus.
This series is arranged chronologically by the predecessor company activity and alphabetically by the name of the community. Gas and electric companies frequently served more than one community so not all information will be found in the file folder for a specific community. Information about the community itself is included as well as details about company and any franchise elections that were held. Cheyenne, Wyoming is listed after all Colorado communities.
Henry Doherty's holding company Cities Service Company took control of hundreds of troubled utility companies across the U.S. He was instrumental in the growth of the Denver Gas and Electric Company and collaborated with Denver Mayor Robert Speer in many activities in Denver and Colorado. Articles and directories associated with Cities Service and the Doherty Men's Fraternity and other Doherty organizations comprise this series, along with the acquisition of companies and papers related to mergers. The series documents the acquisition of part of the assets of Colorado-Ute Electric Association, and the creation of New Century Energies when Public Service Company of Colorado merged with Southwestern Public Service headquartered in Amarillo, Texas. The records documenting the short-lived New Century Energies merger with Northern States Power Company in 1999 to become Xcel Energy Inc. comprise a portion of this series, and are arranged chronologically.
Buildings which housed the company are the final subseries. Specifically the Gas and Electric Company Building (G and E Building) and the Headquarters Office Building (HOB) at 550 15th Street were constructed by the company to house their corporate offices. The move of corporate headquarters to leased space in the 17th Street Plaza are included as well as the 990 Bannock building constructed by the subsidiary Bannock Center Corporation. The Headquarters Office Building was emptied and placed on the market. Failing to find a buyer the company removed all asbestos in the structure and renovated it to consolidate service departments from around the Denver Metropolitan area, it was subsequently renamed the Technical Services Building (TSB). In 2010 space was leased in a newly constructed building at 1800 Larimer where the offices formerly housed in the 17th Street Plaza and Technical Services Building were consolidated along with departments which had previously been officed in buildings throughout the Denver Metropolitan area.
Organization charts and announcements of executive changes are part of this series. A 1994 restructuring resulted in widespread early retirements and job changes. These changes are reflected in this series by lists of those selected for jobs and numerous flyers and memos about retirement parties. Corporate planning programs are also well represented as these were the basis for year to year budget requests.
Department activities include customer sales and marketing, the electric department, employment - including various benefits offered, financial records and rates, gas operations includes gas construction, and gas holders and the development of Leyden Mine as a gas storage facility. Public relations includes company publications, and communications efforts aimed at employees and the general public. Radio program scripts and brochures focusing on the history of Colorado and the communities served within the state form a large portion of this series, but internal memos and planning documents are also well represented. Of particular interest are the earliest financial records of the Denver Gas Company and its subsequent entities. Invoices and vouchers for everything that was purchased in the early years demonstrate the costs and sources of the various products necessary to build a company from scratch. This series includes customer statistics, shareholder information that includes meeting announcements, financial forecasts, and documents regarding the overall business climate in various Colorado communities. The series also contains rate information and fact sheets for employees along with clippings and articles.
The bulk of the sales and marketing portion of this series stems from the early days of the company and efforts to build electric load. Economy of scale was a guiding concept during this period, when the cost of power dropped as more kilowatts were produced.
Power plants are a subdivision of the electric operations and within this subdivision are further subseries: coal fired plants, hydroelectric plants, and the Fort St. Vrain nuclear plant.
The employment department contains some unique records of employment practices no longer used. A handful of personnel files include a detailed assessment of the habits, personality, and performance of the employees during a whole host of training situations. Also included are benefits programs, incentives, education programs, policies, rewards and recognition for performance and safety achievements.
Steam has usually been the forgotten child in this company, and there is little documentation to fill this subseries. Steam, while used to generate electricity within a power plant is also a commodity that heats downtown Denver office and apartment buildings.
The transportation department has been a key component of Public Service Company since its inception. Faced with transmission lines and service territory spanning the Rocky Mountains the challenge of moving people and material safely to and from work sites in the middle of a blizzard or a heat wave has always been a priority. Specially designed and equipped trucks have been a part of the transportation division's responsibility since the early 1900s. Early use of electric vehicles and other innovations and inventions are well represented especially in the photographs, and also in a company publication, Electric Vehicles, that debuted in January 1912.
This series comprises a multitude of projects that Public Service Company employees participated in. While there are extensive photographs of sports activities including bowling, square dancing, basketball, softball, etc. there was a group called Crystal Gazers which had fun with history and predicting financial milestones in the near future. The most accurate predictor and the least accurate headed the group for the following year.
This series comprises a multitude of projects that Public Service Company participated in or was impacted by. Notable among these projects is the Colorado River Storage Project, which was introduced in 1956 and debated for many years. It resulted in the Glen Canyon dam which forms Lake Powell along with other projects in Colorado, Utah, Arizona, New Mexico and Wyoming. In addition, PSCo took an active role with several industry groups including hosting several national conferences. Issues which were of importance to all utility companies are included here with municipal ownership of utilities and nuclear power comprising the bulk of the materials.
The oversize series contains newspapers, especially when special sections were published commemorating the dedication of a facility or an anniversary celebration. A large number of maps showing facilities, transmission lines and pipelines comprise a portion of the series. Charts of predecessor companies, newspaper coverage of franchise elections in many communities and some panoramic photos are in this series too. Diagrams and cutaways of the Leyden Gas Storage Facility and the Fort St. Vrain nuclear power station form part of this series.
Numerous scrapbooks included in this series cover home economics activities, franchise elections and new natural gas projects. Of some note are a number of prints by Ben Cooper, a PSCo staff artist. Cooper painted pictures that portray wildlife, sometimes in proximity to company facilities, but more often simply images of the West. They reproduced these original oils and offered the images to the public through advertisements in 140 Colorado newspapers. They distributed tens of thousands of prints free each year from 1964 to 1978.
Rate case testimony from 1980 comprises a portion of the series, along with a Public Utilities Commission Management Audit conducted in 1982. Ephemera commemorating company mileposts and numerous consumer information brochures explaining various environmental programs and other options offered by the Company constitute a portion of the series.
Several voucher distribution ledgers covering the period 1889-1909 provide documentation of expenditures and costs for general company expenses. Two ledgers from 1939 trace the expenditures for electric operations and details of the expenses incurred at each of the power plants.
This series comprises primarily audio recordings of shareholder meetings from 1964 to 1975. Also contained are audio recordings of the public meeting held in Platteville, Colorado in 1966 when discussion of the proposed nuclear generating station, Fort St. Vrain took place. A few oral history interviews are in this series, including two tapes of Roy Munroe. Several videotapes (in the now obsolete 1/2-inch reel to reel format) of lectures and meetings form part of this series.
Several CD-ROM discs, which must be played on a computer, are in this series. They contain the in-house video news magazine program called In View. Topics range widely and cover both the Northern States Power Company service territory, referred to as North, and the Public Service Company of Colorado and Southwestern Public Service service territories, referred to as Xcel South within the company.
Around 250,000 negatives and prints comprise the Public Service Company of Colorado collection.
A detailed finding aid for the photographs provides access by location, date, and many individuals that have been identified. The photos date from the early 1900s until the late 1990s and cover the entire service territory. The collection is divided into negatives and prints. Negatives are arranged according to the source of the images and then chronologically within that source, most were numbered at the time the photographs were taken and that order has been retained. Prints are arranged by subject, most have a number stamped on the back which relates to the negative number for the roll of film or project from which the print was made. Rarely were all images printed from a single roll of film. When larger format sheet film was used (4x5, 3x4) there was a greater likelihood that a print of each negative was made, usually a contact print. In later years 35mm and 120 roll film was used frequently and contact sheets showing each frame of a roll are common. Often negatives are marked for enlargements on these contact sheets. Contact sheets are filed with the prints by subject. Photos of individuals are filed alphabetically by last name and include studio portraits and other images of that person such as when they receive an award or were photographed for a feature article in Lines magazine or some other publication even if the photos were not used.
Negatives are arranged in several sub series. One large series comprises the work of photographers in the public information department, which later became the public affairs department and eventually corporate communications. This unit worked out of the corporate offices in downtown Denver. Their photos primarily dealt with public relations issues and safety and were often included in various company publications, though some support of operating areas of the company is reflected in the images too. These photos and negatives are marked with a numerical designation reflecting when they were taken (or at least when they were recorded in the photographers ledger). The entry 957-05 indicates the fifth assignment in September of 1957. The number 1265-23 translates to December 1965 assignment 23. The dash (-) is important in determining in which subseries the negative are stored. The dash indicates public affairs. The negatives and prints for most of the photos taken of various accidents at the request of the safety and claims department were turned over to that department. The whereabouts of those images are unknown. In mid 1967 the photographers stopped filing the contact sheets with the negatives so there are fewer prints of the various subjects after that period, especially individual photos of retirees.
A second subseries is referred to as the Danford files because virtually all of the photos were taken by Bill Danford, an employee in the engineering department located in the Holly Service Center east of downtown Denver in the Park Hill area. His photographs bear a similar numerical designation with the exception than an "x" is used in place of the dash. Thus 1257x03 is a photo (or series of photos) taken in December 1957 the third assignment of the month. The public affairs designation system was adopted almost from the outset of the hiring of in-house photographers. The Danford file numbers were added when the database was created, which resulted in a few anomalies in the numbered sequences.
Another subseries is loosely termed "historic" and it bears the distinctive designation of "xx" before the number. The image number xx-0373 is a number relating to the number written on the back of the photo. Many photos have such a number, but many do not. The xx and a lead zero were added to differentiated each photo or group and to be able to enter a unique number into the database. In some cases the image may be a copy negative of an old photo, thus the original and the copy negative might bear different numbers. Some of these photos were taken by contract individuals or companies. Mile High Photo Company and Rocky Mountain Photo Company were frequently hired and they had their own numbering system, which is noted in the database, but is not part of the primary numbering system. The same is true of L.C. McClure and Ed Tangen and other photographers who had their own numbering system. While the photographers number is noted in the database, chiefly to be able to identify identical images, the master number (xx-0000) is purely arbitrary for most of these photos.
There is also another subseries of negatives with a "P" designation. This was done to allow additional photographs and negatives to be linked that were added as the collection was being processed.
A relatively small subseries comprises the Greeley, Colorado based Home, Light and Power Company negatives and prints. The photos and negatives in this group are primarily numbered sequentially, most without any indication as to date taken. The prefix "H" was added to precede each number to identify its place of origin, and unnumbered images have been numbered in an arbitrary sequence beginning with H5000. The H prefix provides a unique number when searching in the consolidated database. Not all of the individual prints and negatives have the "H" physically added to number, but they are present in the database, and the boxes they are stored in provide sufficient separation.
An additional subseries with the prefix "P" comprises photos that were unnumbered but not associated with a particular location. Most of these photos appear to have been taken during or immediately after World War 2 and are a mixture of places, people and different film stocks, some are nitrate and are stored in the freezer, those that are not are stored in an arbitrarily numbered sequence where the negatives are filed by number and the prints are stored alphabetically with other employee photos or by subject or location. For some images the location might be known, typically the time the photos were taken is unknown, attire, vehicles and people within the picture sometimes allow approximately dating the images.
A small subseries with a single x before a number is the code for Newslines photos. In this group X88-140 indicates neither the year or month the photographs were taken, only a sequential number assigned to provide a unique identification. This numbering continued until film ceased to be used in the mid 1990s. Digital images are still held by the company.
Another subseries comprises photo albums. These cover a broad range of subjects, and several are oversize. Most have a theme associated with the album either documenting the activities of a department or a specific construction project.
Another subseries came about after various publication editors began shooting their own photos. They abandoned the established numbering system used since the 1950s. In order to maintain a system of identification of the negatives and prints an arbitrary number was assigned to these photographs and negatives and they were given a designation of x88-000. The negatives and prints were filed separately, but they share the same number. These photos span from 1983 to 1988. Any photos taken by the staff of Visual Services or Visual Communications during this period continued with the system (788-25) already in use.
Another subseries has been numbered by publication date. The editor of Xtra collected the materials when the duties of photographer and editor were consolidated. Negatives and contact sheets were combined with the selected prints from each assignment, and may or may not be identified further.
Numerous nitrate negatives are part of this collection and some have simply disintegrated. Some have degraded to the point of doubtful future use, but the majority are in remarkably good shape and have been frozen to prevent further deterioration. Many of these negatives have contact prints available which will allow easy access without handling the negatives. If nitrate negatives are to be viewed they require 24 hour notice to allow them to be removed from the freezer and attain room temperature before they are handled.
The donation of the photographs was accompanied by many of the publications in which they were used. This was done to allow a researcher to identify people, places, and, in some cases, the purpose of the photographs. A detailed index of Lines magazine has been prepared to help in such searches and many of the photos used are cross referenced with the publication date and page number. Most of these publications have been indexed and the photograph's number is referenced for easy retrieval. Prints have been organized by topic and by an individual's name if there are only one or two people in the photograph, the negatives are in numerical order in the subseries listed above.
Conditions Governing Access
The collection is open for research.
All requests for permission to publish, reproduce, or quote from material in the collection should be discussed with the appropriate librarian or archivist. Permission for publication may be given on behalf of the Denver Public Library as the owner of the physical item. It is not intended to include or imply permission of the copyright holder, which also must be obtained by the customer. The Library does not assume any responsibility for infringement of copyright or publication rights of the manuscript held by the writer, heirs, donors, or executors. Reproduction restrictions are decided on a case-by-case basis.
Biographical / Historical
Forerunner companies to Public Service Company of Colorado (PSCo) date back to 1869 when the Denver Gas Company was formed by some of the early pioneers of Colorado, among them: W.N. Byers, James Archer, Louis Bartels, Walter Scott Cheesman, John Evans, David Moffat, Lewis Tappan and D. Tom Smith. Competing gas companies merged and became the Denver Consolidated Gas Company in 1891. In the meantime the Colorado Electric Company had formed in 1881 which was followed by several electric companies serving small areas or distinct communities and many of these electric companies joined together as the Denver Consolidated Electric Company in 1889. Finally on April 26, 1899, the gas and electric utilities were joined as the Denver Gas and Electric Company as the competition between companies proved an obstacle to continued success.
The Denver Gas and Electric Company waged a battle with Lacombe Electric Company for Denver's business which resulted in ever decreasing rates and profits. As a result both companies were in poor financial condition. In 1902, when Denver Gas and Electric Company was unable to make payment on a $15,000 note a judge placed the company into receivership and appointed Henry L. Doherty, who had been the president of the company for about a year, as receiver. In 1909, Doherty formed Cities Service Company as a holding company, with his newly formed Denver Gas and Electric Light Company as one of its key properties. Doherty's empire grew, but as the Great Depression deepened scrutiny increased. In 1935, the Securities and Exchange Commission restricted companies to two degrees, or layers, thus eliminating the multi corporate pyramids that had been the cornerstone of Doherty's drive to centralize control for greater efficiency and profit. Doherty was vilified by some for the methods he used to acquire power and wealth. Others have hailed him as a management genius in improving the production and distribution of oil, gas, and electricity. He was an inventor and a manipulator. He was an innovative person, whose impact on the utility industry is still felt.
Dozens of small companies merged, were acquired and merged again before the Public Service Company of Colorado (PSCo) was incorporated on August 2, 1923 to build a steam-electric station just outside of Boulder (Valmont station) to provide much needed electricity to northern Colorado and the Denver area. This was the first of three Public Service Companies, which followed very quickly. Public Service Company II formed two months after the first, and was the result of a merger of PSCo I with the Denver Gas and Electric Light Company and the Western Light and Power Company. Public Service Company III was incorporated on Sept. 3, 1924, when PSCo II merged with the Colorado Power Company.
In 1943, the Public Service Company of Colorado became an independent locally owned and operated company and continues as an investor owned utility, operating under the auspices of the Colorado Public Utilities Commission. By 1976, the company represented a composite of more than 80 gas and electric companies dating back to 1869 on the gas side and 1881 on the electric. PSCo serves about 70% of the population of Colorado.
New Century Energies was formed in 1997 when PSCo merged with Southwestern Public Service Company (SPS), based in Amarillo, Texas. Headquarters of the new company was in Denver, Colorado. Then in 1999 Xcel Energy Inc. was formed when New Century Energies merged with Northern States Power Company. The headquarters of the new entity was determined to be in Minneapolis, Minnesota, though Public Service Company of Colorado continues to exist as an operating company of Xcel Energy and is still headquartered in Denver.
- November 13, 1869
- Denver Gas Company incorporated
- April 3, 1879
- Leadville Illuminating Gas Company incorporated
- December 15, 1879
- Denver City Steam Heating Company incorporated
- Boulder Railway and Utility Company formed
- October 14, 1880
- Union Gas Company incorporated in Pueblo
- February 23, 1881
- Colorado Electric Company incorporated
- December 1, 1881
- Georgetown Gas Company incorporated
- August 2, 1882
- Cheyenne Light Company formed
- December 18, 1883
- Brush-Swan Electric Light Company incorporated in Cheyenne, Wyoming
- about 1883
- Leadville Electric Light and Power Company formed
- November 28, 1883
- Cheyenne City Gas Company incorporated
- June 26, 1884
- Boulder Gas Company incorporated
- August 17, 1885
- Greeley Electric Light Company incorporated
- August 17, 1886
- Denver Electric Illuminating Company incorporated
- November 13, 1886
- Green and Clear Lakes Company incorporated
- Peoples Gas Light Company formed
- January 27, 1887
- Pueblo Gas and Electric Light Company incorporated by amending Union Gas Company papers
- May 7, 1887
- Denver Light, Heat and Power Company incorporated
- August 10, 1887
- Edison Electric Light Company of Salida incorporated
- September 14, 1887
- Boulder Electric Light Company incorporated
- Golden Illuminating Company formed
- July 26, 1888
- Gilpin County Light, Heat and Power Company incorporated
- January 17, 1889
- Cheyenne City Gas Company incorporated
- May 7, 1889
- Denver Consolidated Electric Company incorporated
- May 15, 1889
- Monte Vista Electric and Gas Light Company incorporated
- August 8, 1889
- Western Electrical Construction Company incorporated
- December 16, 1890
- Montclair Electric Light Company incorporated
- Del Norte Electric Light and Power Company and Grand Junction Electric and Manufacturing Company formed
- before 1891
- United Gas Improvement Association formed
- March 3, 1891
- Denver Highlands Electric Company incorporated
- April 1, 1891
- Deed of trust upon franchise to George A. Batchelder
- June 6, 1891
- South Denver Electric Light and Power Company incorporated
- October 29, 1891
- Denver Consolidated Gas Company incorporated
- Del Norte Municipal Distribution System Company formed
- before 1892
- Ludolph P. Martin Company formed
- February 26, 1892
- Longmont Electric Light and Power Company incorporated
- April 18, 1893
- United Light and Power Company formed
- March 10, 1894
- Citizens Electric Light Company incorporated
- January 18, 1896
- Leadville Light Company incorporated
- May 26, 1897
- Greeley Power and Light Company incorporated
- January 29, 1898
- Eldora Townsite Company incorporated
- May 24, 1898
- Lafayette-Louisville Electric Company incorporated
- April 22, 1899
- Denver Gas and Electric Company incorporated
- September 5, 1899
- Pueblo Gas Light Company formed by changing name from Pueblo Gas and Electric Light Company
- April 3, 1900
- Lacombe Electric Company incorporated
- May 21, 1900
- Cheyenne Light, Fuel and Power Company incorporated
- May 25, 1900
- Brush-Swan Electric Light Company sold to Cheyenne Light, Fuel and Power Company
- August 30, 1900
- Leadville Gas and Electric Company incorporated
- Erie Electric Distribution System formed
- January 23, 1901
- Loveland Light, Heat and Power Company incorporated
- March 7, 1901
- Cascade Electric Company incorporated (Idaho Springs)
- May 16, 1901
- Boulder Electric Light and Power Company incorporated
- April 25, 1902
- Grand Junction Ice and Cold Storage Company incorporated
- April 29, 1902
- Larimer Light and Power Company incorporated
- May 1, 1902
- Henry L. Doherty appointed receiver of Denver Gas and Electric Company
- May 20, 1902
- Grand River Power and Transmission Company incorporated
- May 28, 1902
- Mutual Electric Light and Power Company incorporated (Alamosa)
- July 31, 1902
- Pueblo Gas and Fuel Company incorporated
- September 10, 1902
- Electric and Hydraulic Company incorporated
- September 16, 1902
- Hydro-Electric Power Company incorporated
- October 20, 1902
- Denver Eureka Power Company incorporated
- December 29, 1902
- O.P. Sells incorporated
- January 26, 1903
- R.G. Munn and R.L. Harper incorporated
- January 27, 1903
- New Century Light and Power Company incorporated
- June 19, 1903
- Colorado Power and Irrigation Company incorporated
- August 4, 1903
- Grand Junction Electric and Gas Company incorporated
- Arapahoe Power and Light Company formed
- March 31, 1904
- Federal Gas Company incorporated
- May 9, 1904
- Citizens Gas and Coke Company incorporated
- May 21, 1904
- Consumers Electric Company incorporated
- July 14, 1904
- Poudre Valley Gas Company incorporated
- August 24, 1904
- Salida Light, Power and Utility Company incorporated
- September 1, 1904
- Henry L. Doherty returns control of Denver Gas and Electric Company to the company
- April 17, 1905
- Edison Electric Light Company of Salida merges with Salida Light, Power, and Utility Company
- January 22, 1906
- United Hydro Electric Company incorporated
- April 3, 1906
- Northern Colorado Power Company incorporated
- November 1, 1906
- Leadville Light and Power Company incorporated
- November 13, 1906
- Central Colorado Power Company incorporated
- November 22, 1906
- Colorado Contracting Company incorporated
- December 15, 1906
- Berthoud Electric Light Company acquired
- Antonito Distribution System formed
- February 11, 1907
- Grand Junction Electric, Gas and Manufacturing Company incorporated
- March 6, 1907
- Palisade Light Heat and Power Company incorporated
- April 6, 1907
- Frederick C. Finkle Company converted
- May 13, 1907
- Eastern Colorado Power Company incorporated
- July 31, 1907
- Summit County Power Company incorporated
- Yak Mining, Milling and Tunnel Company formed
- Brush Electric, Light, Fuel and Power Company formed
- March 25, 1908
- Sterling Public Service Company incorporated
- April 3, 1908
- Lamar Light, Heat and Power Company incorporated
- July 14, 1908
- Sterling Consolidated Electric Company incorporated
- December 21, 1908
- Rifle Light, Heat and Power Company incorporated
- Estes Park Electric Light and Power Company formed
- Arvada Electric Company formed
- March 15, 1909
- Brush Light and Power Company incorporated
- November 23, 1909
- F.W. Fruehauf incorporated
- November 29, 1909
- Denver Gas and Electric Light Company incorporated
- Home Light and Power Company incorporated
- San Luis Power and Water Company formed
- March 30, 1910
- Boyd Lake Reservoir and Irrigation Company incorporated
- September 2, 1910
- Cities Service Company formed
- September 30, 1910
- Eastern Colorado Power and Irrigation Company incorporated
- Newcastle Municipal distribution system formed
- February 14, 1911
- Gas and Electric Development Company incorporated
- April 20, 1911
- Monte Vista Light, Heat and Power Company incorporated
- April 22, 1911
- Brighton Ice, Light and Power Company incorporated
- June 28, 1911
- Palisade Service Company incorporated
- July 11, 1911
- Denver Gas and Electric Light Company formed merging Denver Gas and Electric Company, Lacombe Electric Company, Montclair Light, Heat and Power Company, and the South Denver Electric Light and Power Company managed by Cities Service Company
- Carbondale Light and Power Company formed
- December 2, 1912
- Suburban Light and Power Company name incorporated for Lamar Light, Heat and Power Company serving Aurora
- La Jara Electric and Creamery Company formed
- February 21, 1913
- Central Colorado Power Co. foreclosed
- February 24, 1913
- Leadville Light and Power Company foreclosed
- April 2, 1913
- Colorado Power Company incorporated
- April 12, 1913
- Tonopah Placers Company formed (Breckenridge)
- September 10, 1914
- Western Light and Power Company incorporated
- October 3, 1914
- Grand River Valley Railway Company incorporated
- Garfield Mine Leasing Company formed
- Town of Firestone
- Ft. Lupton Power and Light Company formed
- before 1915
- Grand Junction and Grand River Valley Railway
- Stanley Power Department formed
- Jefferson County Power and Light Company formed
- Gem Electric Company formed
- before 1917
- Evergreen Utilities Company formed
- Saguache Distribution System formed
- Evergreen Public Service Company formed
- May 27, 1918
- Hillcrest Ditch and Reservoir Company incorporated
- December 31, 1918
- Western Light and Power Company acquired by Cities Service Company
- Sedgwick Lighting Company formed
- February 28, 1920
- La Jara Electric Company incorporated
- Big Springs Electric System formed
- Peetz Electric System formed
- Ovid Light and Power Company formed
- Weller Brothers Company formed
- January 10, 1922
- Clear Creek Power and Development Company incorporated
- February 14, 1922
- Raymer Light and Power Company incorporated
- February 23, 1922
- Brush Municipal Electric System formed
- DeBeque Electric System formed
- August 2, 1923
- Public Service Company of Colorado #1 formed
- September 3, 1924
- Public Service Company of Colorado #3 formed by merger with Colorado Power Company
- October 3, 1923
- Public Service Company of Colorado #2 formed with merger of Denver Gas and Electric Light Company and Western Light and Power Company
- September 3, 1924
- Public Service Company of Colorado #3 formed by merger with Colorado Power Company
- Ovid Electric System formed
- Colorado Central Power Company formed
- before 1927
- Rollinsville Electric System formed
- January 17, 1927
- Stanley Power Company incorporated
- June 8, 1927
- Colorado Interstate Gas Company incorporated
- Park Power Company formed
- before 1946
- Town of Bonanza formed
- before 1948
- Redlands Distribution System formed
- before 1952
- Hiway Gas System formed
- Western Slope Gas Company formed
- November 29, 1953
- Local management and operation of Public Service assumed after separation from Cities Service Power and Light holding company
- April 11, 1958
- 1480 Welton, Inc. formed
- before 1961
- Valley Utilities Company formed
- Rio Grande Gas Company formed
- Leadville Utilities Company formed
- Western Slope Gas Company merged with Colorado-Wyoming Gas Company
- September 4, 1996
- PSCo acquires Texas-Ohio Gas Company through wholly owned subsidiary
- December 31, 2010
- Cameo Station in DeBeque Canyon east of Grand Junction ends operations
- November 2011
- Cherokee Unit 2 ends operation as part of Clean Air-Clean Jobs effort in Denver
- April 2012
- Wind fence 1700 feet long and ten stories tall installed at Comanche Station near Pueblo to reduce blowing coal dust
- March 3, 2017
- The last coal is burned at Valmont Station east of Boulder
11 OV Ledgers
Language of Materials
Immediate Source of Acquisition
Gift, Public Service Company of Colorado, 1999-2016. Transfer, History Colorado, 2023.
- Audiovisual materials Subject Source: Art & Architecture Thesaurus
- Electric utilities -- Colorado. Subject Source: Library of Congress Subject Headings
- Organization files Subject Source: Art & Architecture Thesaurus
- Photographs Subject Source: Art & Architecture Thesaurus
- Public Service Company of Colorado -- Archives.
- Public utilities -- Colorado. Subject Source: Library of Congress Subject Headings
- PUBLIC SERVICE COMPANY OF COLORADO RECORDS
- Roger Dudley
- March 2018
- Language of description
- Script of description