Colstrip

History

Colstrip was established by the Northern Pacific Railway in 1924 as a company town to provide coal for their steam locomotives. The mining at Rosebud Mine, two miles south of the town, is open pit strip mining, where draglines remove soil above the layer of bituminous coal from the Fort Union Formation. During The Second World War, the Colstrip mine was identified as strategically important because it supplied coal for the Northern Pacific Railway steam locomotives hauling military equipment for the war effort. The mine was guarded from sabotage, and the employees were not allowed to quit their jobs. In 1958, the railroad switched to using diesel locomotives and the Colstrip mine was shut down. In 1959, Montana Power Company purchased the rights to the mine and the town. It resumed mining operations in the 1970s, with plans to build coal-fired electrical plants. The Rosebud Mine opened in 1968. The power plants were built in the 1970s and 1980s by a collection of contractors including Bechtel. During this construction period, Colstrip was a boomtown, with a large increase in population. Plants 1 and 2 became operational in 1975 and 1976, and plants 3 and 4 became operational in 1984 and 1986. In 1974, construction of Colstrip's Castle Rock Lake (formerly called a surge pond) was completed. The Colstrip plants produce electricity from coal using steam. The water for the steam is pumped in an underground pipe from the Yellowstone River and stored in the lake. The lake is stocked with fish and is the home for a wide variety of wildlife. In 1990, the Colstrip Energy Limited Project began commercial operations. Located six miles (10 km) north of Colstrip, this experimental electricity production facility is owned by Rosebud Energy Corp., a partnership that…

Geography

The Powder River Basin contains the 25,000-acre Rosebud Mine, a strip mine a few miles south of Colstrip, and the Northern Cheyenne Indian Reservation. Bituminous coal lies in the Fort Union Formation. According to the United States Census Bureau, the city has a total area of , all land. There are 30 city parks and 300 acres of green space owned by the city. South of town , is Deer Medicine Rocks, a National Historic Landmark. These sandstone cliffs are covered with petroglyphs and pictographs. Hills covered in sandstone formations are typical of this area. The topography in the county is mostly rolling with small hills. Deer and pronghorn are plentiful.

Race & ethnicity

Most-observed species

• Canada Goose (canadensis Group)

  Branta canadensis (Linnaeus, 1758) · Aves
  67
• American Robin

  Turdus migratorius Linnaeus, 1766 · Aves
  66
• Mallard

  Anas platyrhynchos Linnaeus, 1758 · Aves
  59
• Common Grackle

  Quiscalus quiscula (Linnaeus, 1758) · Aves
  52
• Black-capped Chickadee

  Poecile atricapillus (Linnaeus, 1766) · Aves
  48
• American Coot

  Fulica americana Gmelin, 1789 · Aves
  43
• Northern Flicker

  Colaptes auratus (Linnaeus, 1758) · Aves
  40
• Red-winged Blackbird

  Agelaius phoeniceus (Linnaeus, 1766) · Aves
  40

Most recent

• M 3 — 2026-06-02
  18 km WSW of Colstrip, Montana
• M 3.5 — 2026-05-29
  30 km NNE of Ranchester, Wyoming
• M 3.5 — 2026-04-28
  31 km NE of Ranchester, Wyoming
• M 2.6 — 2026-04-27
  29 km NE of Ranchester, Wyoming
• M 2.6 — 2026-03-30
  26 km ENE of Ranchester, Wyoming
• M 3.4 — 2026-03-27
  33 km NE of Ranchester, Wyoming