The Early Years
As the year 1912 began, it was felt that a circle 100 miles in diameter, with Deadwood in the center, was the territory that should be served by the consolidated electric companies. This included the mining districts in the Black Hills, the Belle Fourche Irrigation Project, and all of the principal cities and important towns of the Black Hills with the exception of Hot Springs which is 75 miles south of Deadwood.
The prairie surrounding the Black Hills averages 3,000 feet in altitude. Some agriculture was carried on in the Hills but the principal industry was mining. Agriculture and stock raising were the principal industries in the prairie country surrounding the Hills. The population of the area served was approximately 60,000.
The following tabulation gives the distribution of the population from 1900 to 1915.
Population State Census
| County | 1900 | 1910 | 1915 |
| Butte County | 2,907 | 4,993 | 5,894 |
| Custer County | 2,728 | 4,458 | 3,452 |
| Lawrence County | 17,896 | 19,694 | 17,710 |
| Meade County | 4,907 | 12,640 | 8,724 |
| Pennington County | 5,610 | 12,453 | 10,040 |
The problems confronting the electric industry early in the twentieth century loomed as big then as do the problems of today. During May and June of 1910, a flood occurred in the Hills that washed out all railroad tracks, and mining operations were nearly suspended until repairs could be made. From December 1909 to March 1910, mining was almost completely stopped due to a "lockout" by the mining companies establishing nonunion labor conditions. Nonunion labor replaced the Western Federation of Miners' Union. Fire destroyed the Mogul Mining Company resulting in loss of large revenues in February 1912.
After World War I, all through the 1920's, and with renewed effort after the worst of the Depression subsided in the late 1930's, electricity was brought to the homes and farms in the Black Hills. Company appliance stores stocked the latest gadgets that used electricity; so load building began with the residential class of customers.
During this period, capacity at the Pluma Plant was increased by installing a 2000 kW steam turbine in 1922 and a 3000 kW steam turbine in 1935. Three boilers were also added. A 5000 kW steam turbine was installed in 1939. In Rapid City a plant was built on Canal Street in 1928. The plant housed a 750 hp McIntosh Seymour internal combustion generator. In 1935, a second internal combustion generator with a capacity of 981 hp was installed. In 1938 a 1000 kW Worthington gas generator was added and in 1940 a 3000 kW steam generator was installed.
In 1929 and 1930, two 120 kW internal combustion units were installed at Custer to operate with the existing 100 hp steam unit. Many distribution lines were constructed in Custer by Henry Oestreich and his crew. A line connecting Custer and Hill City was also built during this time period. In 1938 the line was extended to Keystone and to Big Bend where it was tied in with the steam plant at Rapid City. Consolidated Power and Light Company had transmission lines connecting the distribution system in Deadwood, Lead, Belle Fourche, Central City, Fruitdale, Newell, Nisland, St. Onge, Spearfish, Sturgis, Terraville and Terry. Vale was connected in 1932.
Deadwood was the metropolis and natural center of the Black Hills and was widely advertised as "The Center of the Richest One Hundred Square Miles on Earth."
Gold mining was the principal industry of the Black Hills. A comparative statement of the gold and silver production compiled from the annual reports of the State Inspector of Mines showed the following values:
| 1897 | $5,730,487 | 1908 | $7,544,850 | |
| 1900 | 6,470,156 | 1911 | 7,625,506 | |
| 1902 | 7,342,277 | 1912 | 8,000,000 | |
| 1903 | 7,159,400 | 1986 | 25,000,000 | |
| 1905 | 7,191,553 | 1987 | 34,600,000 | |
| 1906 | 6,986,900 |
The State Mine Inspector's Report showed 3,974 men employed in mines during 1911.
The summer of 1912 was a test of the agricultural possibilities of western South Dakota. The Belle Fourche Irrigation Project began to supply water to the farmers "under the ditch" that spring, and the results were extremely satisfactory. On lands irrigated by this project there were: 11,214 acres of wheat; 5,910 acres of oats; 2,300 acres of corn; 4,840 acres of alfalfa; 4,380 acres of native hay; and 400 acres of potatoes.
A conservative estimate of the crops harvested in the Black Hills area for 1912 was: wheat - 650,000 bushels, oats - 200,000 bushels, corn - 200,000 bushels, alfalfa - 60,000 tons, native hay - 15,000 tons, potatoes - 37,000 bushels. During 1912, the Black Hills area raised enough wheat to supply all local demands. Previously, wheat had been shipped in each year to operate the local flour mills located in Belle Fourche, Sturgis, Whitewood, Rapid City, and Spearfish.
The success of the irrigation project, as demonstrated during the year, would result in a rapid increase in the population of the prairie country surrounding the Hills. Even then it was obvious that stock raising would be an important industry in the country surrounding the Hills. The area was a great natural cattle range and the extent of the industry was indicated by the stock shipments from the district
Butter was manufactured in modern creameries in Deadwood, Belle Fourche, and Whitewood. The manufacture of brooms was a new industry in Belle Fourche. Though the industry was small due to shortage of broom corn, greater quantities in the future were forecasted.
Deadwood was the center of the Black Hills physically, commercially, and politically. It had a splendid hotel, The Franklin, and was the terminal for the Chicago, Burlington, and Quincy Railroad and the Chicago and Northwestern Railway.
Homestake Mining Company in Lead, South Dakota, was the largest mining company in the country and furnished their own power requirements from two hydro-power plants. The 500 kW Englewood Plant transmitted to Lead at 11,000 volts, three phase, 60 cycle power and provided power to operate mining machinery.
The Spearfish Hydro-plant is located on Spearfish Creek, one mile above the town of Spearfish. The development is substantial, consisting of a diverting dam five miles above the plant with a concrete lined tunnel five miles in length through limestone. The water is brought through the tunnel to a surge tank from which it is taken to the powerhouse in steel pipe lines. The equipment consists of three 1500 kW generators directly connected to Pelton water wheels. Current is transmitted to a substation in Lead at 33,000 volts and the power is distributed to mills in Lead at 460 volts for lighting circuits and at 2,300 and 11,000 volts for outlying plants.
Contracts were made with Consolidated Power and Light Company covering the operation of the Pluma steam plant as an auxiliary back-up to the hydro-electric plants.