From introduction: The reconnaissance was made during the summer of 1951 by two field parties: (1) a reconnaissance in parts of Oklahoma, Texas, New Mexico, and Arizona by Russell Gibson, and (2) Geological Survey reconnaissance in parts of New Mexico,.Colorado, Utah, Idaho, and Wyoming (by the writers), the results of which are summarized in this report.

From introduction: Mapping, sampling, and radiometric reconnaissance of the uranium-bearing deposits in the Laramie formation in the vicinity of the Old Leyden coal mine, sec. 28, T. 2 S., R. 71 W., Jefferson County, Colorado (fig. 1), was completed August 10, 1951. Topographic and geologic maps were made of areas approximately 6,000 feet by 3,000 feet (scale 1:2h00), and 1,200 feet by 800 feet (scale 1:600). Underground workings at three clay mines and at the Old Leyden mine were also mapped. With the exception of the 1:600 map, which accompanies this report, these maps will be transmitted later with a more comprehensive report.

From abstract: Eight tons of high grade pitchblende ore was sold from the Jo Reynolds mine near Lawson, Clear Creek County, Colo., in 1919. The pitchblende occurs with silver, lead, and zinc in carbonate-quartz veins cutting pre-Cambrian schist, granite gneiss, and granite.

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 abstract and summary: Long Park and vicinity is in T. 47 N., R. 17 W., Montrose County, Colo. The U. S. Geological Survey started a program of drilling in the area in April 1949, to find deposits that might be developed into new mines and to appraise the reserves of the area. This drilling was done during two periods of time under separate contracts.

From introduction: The present report summarizes the indicated and inferred reserves which have been found to date by the drilling in Club Mesa, Montrose County of New Mexico, and includes an estimate of the potential reserves predicted for the area. It also includes a statement of plans for additional drilling. A final report will be prepared on the completion of the drilling planned for 1951.

From abstract: Recorded production of pitchblende in the United States totals 313 tons of ore containing about 15 percent uranium. Of this total, 303 tons was produced at Central City and 8 tons at Lawson prior to World War I. The remaining 2 tons has been mined at Caribou during the past two years and is being stockpiled at the mine.

From abstract: An investigation of the use of geophysical methods in prospecting for carnotite deposits in the Colorado Plateau was made by the Geophysics Branch of the U. S. Geological Survey between April 21 and June 24, 1949. Results of this preliminary work indicated that electrical resistivity methods could be used successfully.

From abstract and summary: The Blue and Moon Mesa areas are about 13 miles southeast of Gateway, Mesa County, Colo. Total production of carnotite ore from the Blue and Moon Mesa areas has been about 1,000 short tons that averaged about 0.25 percent U30Oand 1.75 percent V205. Most of this production was obtained from 1940 to 1943 and in 1949. The U. S. Geological Survey explored the northern parts of these areas by diamond drilling between August 9 and December 14, 1950. The Survey drilled 113 holes, totalling 16,039 feet. This drilling was mostly wide-spaced and was done to obtain geologic information.

From introduction: The results of Geological Survey exploration at Blue Mesa are summarized in this preliminary report. No additional drilling is planned.

Abstract: Results of detailed mapping of the Salt Wash sandstone member of the Morrison formation in the Uravan and Gateway districts, Montrose and Mesa Counties, Colo., suggest that large areas containing both lenticular bedding in the ore-bearing sandstone and persistently altered mudstone beneath the sandstone are generally favorable for carnotite deposits.

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).

From abstract: An area 2,200 feet long and 400 to 1,300 feet wide within the Haputa ranch, Custer County, Colo., has been mapped at a scale 1:1,200. The rocks in this area consist of quartz-hornblende schist, granite gneiss, hornblende-andesine gneiss, gabbro and peridotite, microcline granite, and pegmatite, of pre-Cambrian age, and lamprophyre dikes of Tertiary age.

Abstract: The Treasure Hill area consists of eight mining-lode claims in secs. 10 and 15, T. 9 N., R. 70 W., Larimer County, Colo. All of the workings were examined and samples were taken from most of them. The results of the examination indicate that there is little or no detectable radioactivity in the schist and granite of the area.

Report issued by the U.S. Bureau of Mines on the oil-shale reserves near the Green River formation. Samples are analyzed for economic value, and presented in tables and illustrations. The report also includes maps of the sample areas.

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 identification of hydrothermal uranothorite from fluorite breccias in Colorado and its comparison/contrasting with other uranothorites and thorites. A description of thorium halos in fluorite is given.

Report discussing "field and laboratory studies of ground-water conditions in the carnotite-bearing Morrison formation in southwestern Colorado and southeastern Utah" with the objective of determining "possible relations between ground waters and the carnotite deposits."

Report discussing the U.S. Geological Survey's investigation of the Calamity group area and the carnotite deposits which are found in this area, often in sandstone.

Report discussing the possible existence of pegmatites containing beryllium deposits in the granite stock in the vicinity of Mount Antero and White Mountain, Chaffee County, Colorado.

"This report describes the geologic and hydrologic characteristics of the ore-bearing sandstone as determined in the core samples from three diamond drill holes on calamity Mesa, Mesa County, Colorado, and correlates these data with localized gamma-ray activity detected in three drill holes."

A report regarding Caronotite Resources of the Calamity Group Area, In Mesa County, Colorado.

A preliminary reserve statement regarding Reserve Blocks B and C, as well as Mineral Channels 10 and 12 of the Outlaw Mesa, located in Mesa County, Colorado.

A preliminary reserve statement of Reserve Block B, of the Long Park Vicinity, located in Montrose County, Colorado.