OF-00-06 Evaluation of Mineral and Mineral Fuel Potential of Chaffee, Gunnison, Lake, and Pitkin Counties State Mineral Lands Administered by the Colorado State Land Board


This open file report for Chaffee, Gunnison, Lake, and Pitkin Counties includes an introduction to the geology and mineral resources of the county along with an index map of tract locations, maps of metallic mineral prospects, industrial mineral prospects, oil and gas test wells and oil field locations, and coal resources. The main body of the report is an evaluation of the resource potential for oil and gas, coal, metallic minerals, and industrial minerals for individual tracts. Digital ZIP download. OF-00-06D

Four general categories of resources are included in this inventory:

  • oil and gas
  • coal
  • metallic minerals
  • industrial minerals and construction materials

Each individual tract evaluation includes:

  • A bar graph which ranks each tract’s resource potential for each of the four mineral categories. An explanation of the categories may be found at the end of this introduction
  • Tract identifier number, county name, and county location map
  • Tract location on a 7-1/2-minute United States Geologic Survey topographic map
  • Tract location on a United States Geologic Survey surface outcrop map
  • Location as to section, township, and range and approximate acreage
  • Overview of tract geology
  • Specific assessment of the resource potential for the four resource categories
  • References used in assessing tract potential

This evaluation of the mineral and mineral fuel resource potential was conducted for the nearly 42,000 acres of state mineral lands within Chaffee, Gunnison, Lake, and Pitkin Counties in mountainous west-central Colorado. It was conducted as part of its long-term evaluation of approximately 4 million acres of state lands administered by the State Land Board. For evaluation purposes, the counties were divided into 62 individual tracts that range from approximately 40 acres to 4,333 acres. Thirty-four tracts are in Gunnison County, eighteen are in Chaffee County, and Pitkin and Lake Counties each have five tracts.

Mining has played an important part in the colorful history and economic development of all four of these mountain counties. The towns of Aspen, Crested Butte, Leadville, Salida, and many lesser known settlements all began as mining and ore processing centers in the nineteenth century. Many mineral products have been produced, including gold, silver, molybdenum, lead, zinc, copper, coal, marble and granite.

Mining activities in these counties, as of 2000, included numerous sand, gravel, and aggregate pits, intermittent quarrying of the world-famous marble near the town of Marble in Pitkin County, a new alabaster quarry recently permitted in Pitkin County, and two major coal mines on the western edge of Gunnison County near Somerset. Wells in the western part of Pitkin County and northwestern Gunnison County produce natural gas.

Oil and natural gas is produced in extreme western Pitkin County and northwestern Gunnison County. All productive wells are located in the Piceance Basin structural province. However, no wells have been drilled on state land.