History of Energy in Montana

Montana's Energy History


The early history of electricity development in Montana is closely tied to the servicing of mining and the industrial processing of ores and minerals. The development of large hydroelectric facilities dominates the three decades following 1900. Industrial demand for electricity expanded in the mid-twentieth century as oil refineries and both crude oil and refined product pipelines arrived.

Postcard of first Canyon Ferry Dam and Powerhouse, built in 1898


The Rural Electric Administration was authorized in 1936 and electric cooperatives were formed on both sides of the Continental Divide. The Bonneville Power Administration was formed during this era and remains a major influence, mostly west of the Continental Divide. Other federal players include the U.S. Army Corps of Engineers’ hydroelectric projects at Fort Peck on the Missouri and Libby Dam on the Kootenai River, and Bureau of Reclamation hydroelectric dams at Canyon Ferry on the Missouri and at Hungry Horse on the South Fork of the Flathead.

Small scale thermal generation of electricity dates to Montana’s territorial era. As hydroelectric opportunities diminished in the mid-Twentieth Century, utilities looked increasingly to eastern Montana’s coal deposits as an energy source. The transmission of electricity in the region first developed to carry electricity from the hydroelectric facilities to the industrial centers. In a similar fashion, later transmission lines would export surplus electricity to out-of-state markets, eventually including power generated at the coal-fired thermal plants at Colstrip. 

The earliest mining in Montana Territory focused on placer deposits of gold, which tended to play out early. Later extraction of gold, and particularly silver and copper, entailed crushing and milling, high temperature roasters, smelting and other forms of processing to separate valuable ores from background minerals. Wood charcoal, coal, and coked coal were used heavily in the decades prior to 1910 to process minerals. Mechanical power to run the mines was mainly provided by on-site stationary steam plants that compressed air to power many of the mining functions and generated electricity for lighting and water pumping. By 1915, electricity had taken over the powering of most mining, milling, and processing functions.

Electric Lighting

Electric lighting was the earliest commercial application in Montana, as was the pattern elsewhere in the country. Above-ground operations at Marcus Daly’s Alice mine in Walkerville (Butte Mining District) were illuminated by arc lights as early as 1880. These bulbless, direct current (DC) dynamos and lamps were pioneered and promoted by Cleveland inventor Charles F. Brush, who franchised and licensed the system to local companies for municipal and commercial use. The Brush Electric Light and Power Company was formally organized in Butte in 1882 with William Andrews Clark elected president and Patrick A. Largey a trustee. Both men would figure prominently in copper mining and banking as the electric era got underway in Montana. The company would introduce Edison-style enclosed bulb lighting at the exclusive Silver Bow Club in 1885. Both Butte and Helena had coal-fired electric works plants by the late 1880s, mostly for municipal and commercial lighting. By 1890, Butte would have two competing electric lighting companies and two modern coal-fired steam generation plants. Larger industrial concerns continued to operate and maintain their own lighting generators.

Early Hydroelectric Dams

The explorer William Clark performed a rough survey of the Great Falls of the Missouri as the expedition passed through in 1805. His journal entry notes, “from this survey, the Missouri experiences a descent of 360 feet 2 inches” over roughly 13 miles. Ninety years later the state’s first hydroelectric dam would be built out of timber cribs filled with rock at Black Eagle Falls. The Boston & Montana Company wanted to site a new smelter at Great Falls to process silver and other hard-rock ores. The company agreed to finance and build its own power house while the Great Falls Water Power and Townsite Company would construct the dam and built a separate power house across the river to serve municipal requirements. The electric plants were commissioned in 1891 and 1892. Mechanical power was also delivered from the facility during the initial years.

Another early hydroelectric project was a dam on the Missouri River seventeen miles east of Helena near today’s Canyon Ferry. The rock-filled wooden-crib structure provided 30 feet of head to four Westinghouse 550-kilowatt generators. The plant began operation in 1898 with tests at a smelter at East Helena. The facility initially furnished electricity to the Capitol over a double circuit powerline. The plant was upgraded in 1901 and two wood-pole transmission lines were built to Butte and Anaconda in 1902. The principal behind the Helena power company was former Territorial Governor Samuel T. Hauser. The bold move to build transmission to the Butte-Anaconda district was assisted by stockholder W.A. Clark through contracts to his mining and processing holdings. Clark almost certainly assisted Hauser in financing the dam at Canyon Ferry and a later project called Hauser.

Most of Montana's towns of this era formed electric lighting companies and one source indicates as many as 40 were on record at one time or another. In Butte, the two competing companies merged with the General Electric Company in 1893. Upstarts continued to emerge, however. One notable joint venture formed to build a dam and waterpower plant on the Big Hole River near Divide. The company negotiated a contract to deliver electricity from the Big Hole to the Butte General Electric Company.

The dam the company constructed on the Big Hole River at Divide was badly damaged in the spring of 1898 and the company failed. Remaining Big Hole River assets were essentially absorbed by Butte General Electric. Two unused 750-kilowatt hydroelectric generators were shipped to Butte where they were temporarily assigned to generate electricity from coal-fired steam. The reconstructed dam on the Big Hole was completed by Butte General Electric at the very end of 1899 and the generators were returned to the site at Divide.

Transmission Considerations

The Phoenix Electric Company was an early competitor of the newly formed Butte General Electric and a former principal of the company purchased water rights on the Madison River with an eye toward hydroelectric generation. Engineers were dispatched to the site at the head of Beartrap Canyon and in the spring of 1900 a rudimentary dam, flume, and stone power house were constructed. Two General Electric 1,000-kilowatt generators made use of the 22-foot of head from the penstock and two parallel wood-pole power lines were completed to Butte in early 1901. The assets of the Madison River venture would eventually be purchased by the reformulated Butte Electric and Power Company.

Transmission lines of this era generally featured treated wooden dowels or “pins” inserted vertically into a crossbeam in the fashion of earlier telegraph lines. These pins were often threaded to support hardened glass, and later porcelain ceramic insulators that contacted the electric lines. Later “strain” insulators better handled weight and movement of the lines. The introduction of suspension insulators around the turn of the century allowed for higher voltage transmission. One multi-part bell-style suspension insulator was patented by Butte resident and early Montana Power Company engineer Harry H. Cochrane in 1915 and was used exclusively in Montana. Cochrane Dam on the Missouri downstream of Great Falls is named for him.

From an early Montana Power Company line supply catalog


Uses for electricity grew quickly in the 1890s. Helena had an electric street railway by 1890. By the late 1890s, a small portion of electricity sales by Butte General Electric (later Butte Electric and Power Company) were being used to pump water. At about this time, electric motors started to replace steam engines to compress air for use in the mines as well as for milling and concentrating. Electric hoist motors were about the last application to arrive to mining in Butte, beginning around 1905. Heavy strains for short periods (up to 13 tons), absolute reliability, and delicate control were demands compounded by the large number of hoist houses on the Butte Hill that might draw simultaneously from a limited electricity delivery system. Direct current hoist motors were gradually worked into the mix alongside electric-generated compressed-air hoists. The electrical load supplied to Butte in 1915 was confined almost entirely to mining, the power being used chiefly for the operation of motor driven air compressors and electrically driven pumps.

In the 1890s the played-out placer gold district downstream from Virginia City saw a resurgence of activity as steam-powered dredges worked lower Alder Gulch. Large scale processing of streambed rock was important for this type of mining and engineers began to look to newer electric motors to approach the work. In 1906, the Conrey Placer Mining Company built its first electric-powered dredge. By 1911, four giant dredges powered by electricity generated at the Madison Dam would process the gravels of Alder Gulch. The largest dredge had a total electric motor rating of 1,285 horsepower. Another nearby concern to purchase Madison River electricity was the Portland Cement Company at Three Forks which first contracted for electrical power in 1907.

Butte had four smelters in the late 1880s to process rich ores that ran upward to 30 percent copper. These early smelters used wood charcoal and later coked coal. As copper percentages declined over time, a series of large, centralized smelters were built in Anaconda. Copper ores were processed with both fluids (hydrometallurgy) and heat (pyrometallurgy). Electricity was used for pumping, crushing, grinding, and conveyance. Electric furnaces for roasting and smelting were eventually introduced at the Anaconda smelters. Electrolytic refining began in the late 1890s, which further improved the quality of Montana copper and its market position. The Anaconda Company moved its electricity-intensive refining processes entirely to Great Falls just after the turn of the century.

A 1988 Office of Technology Assessment report commissioned by Congress contains a chapter: Energy Use in the Copper Industry.  Historically, “mining uses about 20 percent of the total energy requirements; milling around 40 percent; and smelting, converting, and refining the remaining 40 percent."


As more industrial applications arrived for electricity, the Helena, Butte, and Great Falls companies rushed to build new dams and to improve existing dams. Five main players emerged from the many small power companies of previous decades: Butte Electric & Power, Madison River Power (merged in 1905), Missouri River Electric & Power, Helena’s Missouri River Power (bankrupt in 1908), and Billings Eastern Montana Power.

Sam Hauser’s Helena-based Missouri River Power Company built a steel-plate dam on the Missouri downstream from the existing Canyon Ferry facility in 1907. With two dams and contracts in Butte and Anaconda, Hauser’s company seemed poised to break out as the major player in Montana electricity generation and transmission. However, the new dam collapsed during the 100-year flood event of 1908, although poor engineering was also cited. The financial fallout of this failure led indirectly to the forming of the Montana Power Company.

The holding company over the Anaconda Company was reluctant at this time to overtly enter the race to build hydroelectric dams. The company held a million dollar interest in the failed Hauser Dam, which probably confirmed this outlook. The Anaconda Company could agree to generous contracts for electricity, however. Furthermore, its president since 1905, John D. Ryan, was personally invested in hydroelectric development. Around 1907, Ryan and partner John G. Morony formed an investment pool to purchase rights and develop more dams on the Missouri near Great Falls. Ryan maintained later in life that his interest in hydroelectric development was strictly to serve the needs of the copper mining company. Ryan was instrumental in the construction of Rainbow Dam outside of Great Falls, which was completed in 1910 in less than 20 months. He also ordered the building of a major transmission project, known as the Rainbow Line, to ship power from the facility to the Butte-Anaconda area. Completed in 1910 and using 2,400 metal lattice towers, the high-tension twin lines were installed with modern suspension insulators. The 100-kilovolt lines remain in service more than a century later. One span over the Missouri River is more than 3,000 feet; 665 tons of copper wire was suspended along the lines.

First Hauser Dam failure, April, 1908


Ryan moved aggressively to consolidate the various interests as Hauser’s venture went into receivership. By 1911, he had formulated control over all Missouri River development rights as well as the remnants of Hauser’s failed company. In 1912 and 1913, Ryan brokered a merger with the remaining electric companies that would form Montana Power Company. The final negotiations were with General Electric, which held a substantial interest in the Butte power company. Ryan served as Montana Power’s first president following the consolidation.

Ryan also served on the board of directors of the Chicago, Milwaukee & St. Paul Railroad (Milwaukee Road) during this time and helped that company purchase the rights to hydroelectric power at Thompson Falls along its route through Montana. The company had decided to power its line between Harlowton, Montana and Avery, Idaho with electric locomotives. At some early juncture, the Milwaukee Road decided to purchase electricity from Montana Power rather than generate its own and Ryan bought back these development rights. The Anaconda Company’s short-line railroad known as the Butte, Anaconda & Pacific also converted to electric locomotives in 1913.

Montana Power moved to build Volta Dam (later named Ryan Dam) outside of Great Falls, which was completed in 1915. The company also worked to complete Thompson Falls Dam on the Clark Fork River, which also came online in 1915. An upgrade to Rainbow Dam was implemented in 1918 with additional generation. Holter Dam on the Missouri was also completed in 1918.

As noted previously, William A. Clark was an investor in the first power company in Butte in the 1880s. He purchased outright the Missoula Light and Power Company in 1906 and moved to build the Clark Dam just downstream from the confluence of the Blackfoot and Clark Fork Rivers. The dam was completed just in time for the major flood year of 1908; it survived the flood with some damage and the powerhouse was out of commission throughout that summer. (This dam, later known as Bonner Dam, was removed in 2010.) Clark maintained his interest in the Missoula power company until his death in 1925. These holdings were eventually purchased by Montana Power Company.

Clark Dam at Bonner during the flood of 1908. Later known as Milltown Dam, it was removed in 2010


The Montana Power Company began construction at the Kerr Dam site just downstream of Flathead Lake just as the Great Depression was gaining traction and work was stopped in 1931. It was resumed in 1936, however, and the project was completed in 1938. Additional generation was added in 1949 and 1954 after completion of the federal Hungry Horse Dam project on the South Fork of the Flathead River above Flathead Lake.

In eastern Montana, the Montana Power Company secured permits to build hydroelectric generation at a string of high-altitude lakes at the head of the Rosebud tributaries of the Stillwater River in the Beartooth Mountains. These dams and powerhouse were complete by 1926 with much of the electricity sent to Northern Pacific’s new mining venture at Colstrip where large electric-powered draglines strip-mined coal seams.

The Fort Peck Dam project was authorized in 1933 by President Franklin D. Roosevelt as part of New Deal-era relief legislation and work began almost immediately. The dam was originally envisioned as a combined jobs project in the depths of the Great Depression and as a facility for flood management and downstream transportation. The dam was constructed by the Army Corps of Engineers using a steel curtain piling wall across the river enclosed with dredged rock, gravel, and shale fill. The dam is 250 feet from its base to the top. The project closed within three years, but full pool was not attained until 1941. Four tunneled intake structures serve hydroelectric generators that were installed in increments between 1943 and 1961. For more information on hydroelectric facilities in Montana, visit: our Hydroelectric Portfolio site.

Early Thermal Generation

As previously mentioned, much of the early electric generation was on-site, small-scale steam generation for industrial and municipal lighting. Most industrial, commercial, and later residential applications were eventually serviced through the Montana Power Company’s network of efficient hydroelectric facilities. In much of Montana, coal was expensive to mine and transport and its use was largely reserved for industrial and rail transportation purposes. The growth of Billings in the mid-twentieth century proved too much for that region’s limited hydroelectric opportunities, and planners looked increasingly at nearby coal fields.

A water wheel was at work in Billings generating electricity from a canal on the Yellowstone River in the late 1880s. In 1906 a low-head dam and generating facility was built on the river, but it was plagued by ice jams in winter and had to be supplemented by a coal-fired steam plant. The Billings Water Power Company built a 12-foot dam on the same site in 1907 with an upgrade the following year. A 500-kilowatt modern steam generator was installed in 1909 to back-up the hydro power. Transmission lines were extended to the Northern Pacific shops in Laurel and later a connection was completed with the Madison Dam transmission system.

The city of Billings would grow from roughly 10,000 people in 1910 to almost 32,000 in 1950, in part due to development of the area’s natural gas and oil fields and oil refineries. Three large oil refineries in the Billings area became a new market for electricity. By the late 1960s these refineries were using approximately 25 megawatts, up from 3.5 megawatts in 1950. Pumps along the crude oil lines feeding the refineries and the product lines moving fuels out of state also used electricity. The Yellowstone Pipeline from Billings to Spokane used about 7.5 megawatts to power five pumps during this period and a crude oil line running from Alberta into Wyoming used more than 11 megawatts to power a dozen pump stations. The Montana Power Company needed more generation in the area to meet the growing load.

In his History of the Montana Power Company, author Cecil Kirk, writing in the late 1960s, noted:

There were several reasons for building the steam plant in Billings. First the Billings area needed more generation and steam was the only answer there. Secondly, a good source of fuel oil was available from the Billings refineries, and a source of gas was available in the Dry Creek Field. Third, cooling water was available from the Yellowstone River. And finally, [the Montana Power Company] needed a back-up source of power for its hydro-plants in case of low water or sudden freeze-ups. Billings seemed the ideal location.

A 70-megawatt thermal plant designed to run on either natural gas or oil was completed in late 1951 and named for the Montana Power Company president of the time, Frank Bird. An 8-inch crude oil pipeline from the Dry Creek field near Red Lodge was converted to carry natural gas to the new plant. A second single-boiler thermal plant would follow in 1968 – the Corette Plant – engineered to fire by coal. The J.E. Corette Steam Plant remained operational through 2013 at about 180 megawatts; it was decommissioned and has been dismantled. The Bird plant was taken out of service in the 1980s after a number of years of intermittent use.


Montana’s ability to generate electricity for its own uses and for export to neighboring states and provinces is thanks largely to the luck of geography and geology. High elevations along the Continental Divide collect precipitation as snow, which runs off primarily through the Missouri and Clark Fork of the Columbia River systems. Hydroelectric facilities built on Montana streams conservatively deliver close to 2,600 megawatts of electricity (wintertime capacity). Similarly, the massive coal deposits that underlie much of the state contribute another 2,400 megawatts of steam-generated electricity. The renewable energy of wind made an impressive entry into the state’s overall electricity portfolio in recent years and is covered in the history of renewable energy section.

The load profile for the state’s electricity consumption has changed greatly since the early years of mining, smelting, and refining of minerals such as copper. Mineral mining and processing remains a small use for electricity in Montana, while the industrial load centers have shifted or closed operations. Commercial and residential consumption has risen in the post-War decades, both in Montana and in the export markets out of state. More recently, new loads have risen to accommodate the digital, semiconductor, and photovoltaic sectors – data processing centers, for example, and polysilicon and silane gas manufacturing.

Works consulted

The Butte Daily Miner, November, 1880

Kirk, Cecil, A History of the Montana Power Company, 2008

Johnson, C., Energy-Power, Copper, and John D. Ryan, Montana the Magazine of Western History, 1988

American Institute of Mining Engineers, meeting program, Butte, 1913

U.S. Patent Office No. 1,194,957, Insulator, April, 1915 and: www.glassian.org/suspension/index.html 

Russell, H., Electric Hoists for Mine Service, Mining and Scientific Press, 1913

Jennings, H., Janin, C., The History and Development of Gold Dredging in Montana, Bulletin 121, Bureau of Mines, 1916

Copper: Technology & Competitiveness, Office of Technology Assessment, 1988

Marcosson, I., Anaconda, 1957

Quivik, F., Early Steel Towers and Energy for Montana's Copper Industry, Montana the Magazine of Western History, 1988