From introduction: From November 1949 to May 1952, the U. S. Geological Survey explored the Spud Patch area by diamond drilling to find carnotite deposits that would make new mines and to appraise the reserves of the area. Previous work and a brief outline of the general geology of the area have been reported (Bell and Icke, 1950; and Bell, 1952).

From abstract: A reconnaissance radiometric survey of parts of the northwestern San Juan Mountains has revealed the occurrence of uranium-bearing ores in several mining districts in Ouray and San Juan Counties, and the occurrence of thorium-bearing veins in southwestern Gunnison County.

From introduction: This preliminary report summarizes the results of the 1950 drilling in the Legin group area of San Miguel County, Colorado and gives a more complete, but preliminary, estimate of the uranium and vanadium ore reserves. When the radiometric and chemical assay data are completed, a detailed report will be transmitted.

From introduction: The results of U. S. Geological Survey exploration in the Legin group area are summarized briefly in this preliminary report. No additional drilling is planned. The Legin group area comprising nine Government-owned claims, three privately owned claims and adjoining public land, is in San Miguel County, Colo. The area explored includes parts of secs. 28 and 29, T. 43 N., R. 19 W., New Mexico principal meridian (fig. 1).

The Uranium Mill Tailings Radiation Control Act of 1978 (42 USC {section}7901 et seq.), hereafter referred to as the UMTRCA, authorized the US Department of Energy (DOE) to clean up two uranium mill tailings processing sites near Slick Rock, Colorado, in San Miquel County. Contaminated materials cover an estimated 63 acres of the Union Carbide (UC) processing site and 15 ac of the North Continent (NC) processing site. The sites are within 1 mile of each other and are adjacent to the Dolores River. The sites contain concrete foundations of mill buildings, tailings piles, and areas contaminated by windblown and waterborne radioactive tailings materials. The total estimated volume of contaminated materials is approximately 621,300 cubic yards (yd{sup 3}). In addition to the contamination in the two processing site areas, four VPs were found to contain contamination. As a result of the tailings being exposed to the environment, contamination associated with the UC and NC sites has leached into shallow ground water. Surface water has not been affected. The closest residence is approximately 0.3 air mi from either site. The proposed action is to remediate the UC and NC sites by removing all contaminated materials within the designing site boundaries or …

This proposed remedial action plan incorporates the results of detailed investigation of geologic, geomorphic, and seismic conditions at the proposed disposal site. The proposed remedial action will consist of relocating the uranium mill tailings, contaminated vicinity property materials, demolition debris, and windblown/waterborne materials to a permanent repository at the proposed Burro Canyon disposal cell. The proposed disposal site will be geomorphically stable. Seismic design parameters were developed for the geotechnical analyses of the proposed cell. Cell stability was analyzed to ensure long-term performance of the disposal cell in meeting design standards, including slope stability, settlement, and liquefaction potential. The proposed cell cover and erosion protection features were also analyzed and designed to protect the RRM (residual radioactive materials) against surface water and wind erosion. The location of the proposed cell precludes the need for permanent drainage or interceptor ditches. Rock to be used on the cell top-, side-, and toeslopes was sized to withstand probable maximum precipitation events.

The US Environmental Protection Agency (EPA) has established health and environmental protection regulations to correct and prevent ground water contamination resulting from processing activities at inactive uranium milling sites (52 FR 36000 (1987)). According to the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, 42 USC {section}7901 et seq., the US Department of Energy (DOE) is responsible for assessing the inactive uranium processing sites. The DOE has determined that for Slick Rock, this assessment shall include hydrogeologic site characterization for two separate uranium processing sites, the Union Carbide (UC) site and the North Continent (NC) site, and for the proposed Burro Canyon disposal site. The water resources protection strategy that describes how the proposed action will comply with the EPA ground water protection standards is presented in Attachment 4. The following site characterization activities are discussed in this attachment: Characterization of the hydrogeologic environment, including hydrostratigraphy, ground water occurrence, aquifer parameters, and areas of recharge and discharge. Characterization of existing ground water quality by comparison with background water quality and the maximum concentration limits (MCL) of the proposed EPA ground water protection standards. Definition of physical and chemical characteristics of the potential contaminant source, including concentration and leachability of …

From abstract: The Legin group area comprises five privately owned claims, nine Government claims, and some public land. The area is in parts of secs. 28 and 29, T. 43 N., R. 19 W., New Mexico principal meridian, San Miguel County, Colo. It is about 45 miles from the Government mill at Monticello, Utah, and 50 miles from the Vanadium Corporation of America mill at Naturita, Colo. The Legin group area has yielded a total production of more than 18,000 short tons of carnotite ore that averaged 0.32 percent U30 and 2.5 percent V 205 . Most of this production was accomplished during the years from 1935 to 1944, and from 1949 to October 1951.

Report discussing the exploration of the Upper group area in San Miguel County, Colorado, and the investigation of carnotite ores produced from this area.

Report discussing the investigation of uraniferous pyrobitumen deposits found at mining sites at the Weatherly and Robinson properties by Placerville, Colorado.

Report discussing an exploratory drilling program in the Charles T. area and vicinity during the period from November 1947 and September 1949. "The purpose of the exploration was to discover new carnotite deposits to support milling operations on the Colorado Plateau, and to appraise the uranium and vanadium resources of the area explored."

Report discussing the regional geology, geomorphology, structure, mineral deposits, and details of the sedimentary and igneous rocks of the Placerville Quadrangle in Colorado.

Report discussing the geology and ore deposits of the Placerville area of San Miguel County, Colorado. "This report is an abstract of a paper with the same title that is planned for publication as a Geological Survey bulletin."

Report discussing the contact and weathering of the Burro Canyon formation shales and Dakota sandstone as well as other connections of the Burro Canyon formation.

The following report covers a study of the electrical properties of the Morrison formation in the Uravan mineral belt of the Colorado Plateau province where it is indicated that there is a significant correlation between electrical resistivity and the relative favorability for occurrence of ore. This report presents the measurements of resistivity trends.

Report discussing the geography and ores of the Spud patch area, which acted as a source of carnotite ore from deposits in a sandstone lens.

Preliminary geologic map of the Placerville quadrangle, Colorado.

This baseline risk assessment of ground water contamination at the uranium mill tailings sites near Slick Rock, Colorado, evaluates potential public health and environmental impacts resulting from ground water contamination at the former North Continent (NC) and Union Carbide (UC) uranium mill processing sites. The tailings at these sites will be placed in a disposal cell at the proposed Burro Canyon, Colorado, site. The US Department of Energy (DOE) anticipates the start of the first phase remedial action by the spring of 1995 under the direction of the DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project will evaluate ground water contamination. This baseline risk assessment is the first site-specific document for these sites under the Ground Water Project. It will help determine the compliance strategy for contaminated ground water at the site. In addition, surface water and sediment are qualitatively evaluated in this report.

This report sumarizes the results of the US geological survey exploration in the Bull Canyon district from October 1955 to April 1956

A preliminary reserve statement regarding Reserve Bocks 1, 2, and 3, of the Veta Mad and Veta Glad Claims, Georgetown group, located in San Miguel County, Colorado.

A report regarding Preliminary reserve statement 21, reserve blocks A and B, Spud Patch area, San Miguel County, Colorado

A preliminary reserve statement, regarding Reserve Blocks B and C, located in the Legin group Area, in San Miguel County, Colorado.

A preliminary reserve statement regarding Reserve Blocks H, F, and G, of the Legin Group Area, Located in San Miguel County, Colorado.

A report regarding development drilling on the Tiny claim, Gypsum Valley district, San Miguel County, Colorado