This open-file report for Douglas and Elbert 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, coal resources, and oil and gas test wells and oil field locations. The main body of the report is an evaluation of each individual tract, which includes text as well as a topographic map and a geologic map. Digital ZIP download. OF-03-10D
Four general categories of resources are included in this inventory:
- oil and gas
- 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
From the Report:
Douglas and Elbert Counties are in east central Colorado. Douglas County is located both in the Front Range and the Denver Basin; whereas all of Elbert County lies within the Denver Basin. This evaluation of the mineral and mineral fuel resource potential was conducted for approximately 167,000 acres of state mineral lands located in the two counties. 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 two counties were divided into 145 individual tracts that range from approximately 40 to 14,480 acres in size.
No oil or gas fields have been discovered in Douglas County as of the date of this report. In 2002, Elbert County ranked 21st among Colorado’s counties in cumulative oil production and 27th in cumulative natural gas production from a total of 24 producing fields. The eastern half of Douglas County and the western three-quarters of Elbert County are within the Denver coal region. Several coal fields were mined in the past in the two-county area.
Gold has been mined in the past from placer deposits in streams that are tributary to Cherry Creek in northeastern Douglas County. Low-grade manganese oxide deposits are present within the Tertiary Dawson Arkose at a few places in Douglas County. Pegmatites in the Proterozoic granitic rocks in the Front Range foothills of western Douglas County locally contain sub-economic quantities of rare earth elements (REE) and beryllium. Gem and specimen-quality topaz and amazonite has been found in a few of the Devil’s Head pegmatites as well (Hanley and others, 1950).