From summary: This data release presents analytical results obtained for a pilot study being done in portions of the Sterling and Greeley, Colorado, National Topographic Map Series (NTMS) quadrangles (Fig. 1) by the University of Colorado under contract to the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

From introduction: This report describes work done in the Sterling, Colorado, National Topographic Map Series (NTMS) quadrangle (1:250 000 scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

From introduction: This report describes work done in the Pueblo, Colorado, National Topographic Map Series (NTMS) quadrangle (1:250 000-scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

From introduction: This report describes work done in the Denver and Greeley National Topographic Map Series (NTMS) quadrangles (1:250 000 scale) by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

Abstract: Multivariate statistical analyses were carried out on Hydrogeochemical and Stream Sediment Reconnaissance data from the Craig quadrangle, Colorado, to support the National Uranium Resource Evaluation and to evaluate strategic or other important commercial mineral resources. A few areas for favorable uranium mineralization are suggested for parts of the Wyoming Basin, Park Range, and Gore Range. Six potential source rocks for uranium are postulated based on factor score mapping. Vanadium in stream sediments is suggested as a pathfinder for carnotite-type mineralization. A probable northwest trend of lead-zinc-copper mineralization associated with Tertiary intrusions is suggested. A few locations are mapped where copper is associated with cobalt. Concentrations of placer sands containing rare earth elements, probably of commercial value, are indicated for parts of the Sand Wash Basin.

Report describing chemical analysis of 62 water and 620 sediment samples during a follow-up geochemical survey to search for uranium in the Pueblo quadrangle.

From introduction: This report describes work done in the Durango National Topographic Map Series (NTMS) quadrangle, Colorado, by the Los Alamos Scientific Laboratory (LASL) as part of the nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR).

From summary: The University of Colorado, under contract with the Los Alamos Scientific Laboratory (LASL), is currently performing an evaluation of geochemical relationships of water and sediments and seasonal variations to uranium for the South Platte drainage of northeastern Colorado. As a preliminary part of this study, samples were collected from 125 sites near Sterling and Fort Morgan, Colorado, during the period from December 20, 1976, to January 15, 1977. During this period the weather in the area was clear to partly cloudy, with daytime temperatures ranging from -12 to 12 C. Only a trace of precipitation, in the form of very light snow flurries, occurred during the sampling period. The sample site locations and numbers (the first two digits have been omitted) are shown on Plate I.

A report regarding a survey of the condition of wells and springs in the Rio Blanco County, in N.W. Colorado.

The following report studies uranium ore deposits discovered in the Browns Park Formation, south-central Wyoming and northwest Colorado.

"The principal uranium deposits in southcentral Wyoming and north-western Colorado are located in or at the margins of broad Tertiary basins. Interesting and possibly commercially significant occurrences are found in other Tertiary and older rocks at widely separated locations within this region. The six maps accompanying this report give the location, name, and ownership of the mines and occurrences from which samples assaying greater than 0.10% U3O8 have been collected. Claim names, location, and ownership are also given for occurrences outside the map areas."

Index maps, detail figures, columnar sections, and calculation tables for the Carpenter Ridge District.

Figures and columns for the West Paradox District.

A report regarding the Lightner Creek District in the San Juan Basin Area, Colorado.

Analysis of geologic, hydrologic, and geophysical data obtained in and around Yellow Creek core hole No. 1, Rio Blanco County, Colorado, indicate a 1,615-foot section of oil shale was penetrated by the hole. Geophysical log data indicate the presence of 25 gallons per ton shale for a thickness of 500 feet may be marginal. The richest section of oil shale is indicated to be centered around a depth of 2,260 feet. Within the oil shale the interval 1,182 to 1,737 feet is indicated to be relatively structurally incompetent and probably permeable. Extension of available regional hydrologic data indicate the oil shale section is probably water bearing and may yield as much as 1,000 gallons per minute. Hydrologic testing in the hole is recommended.

The following slides document black sand deposits that were analyzed in the parent report, Radioactive Titaniferous Heavy Mineral Placers in the San Juan Basin, New Mexico and Colorado.

The following document contains the 17 figures in relation to the report, Environment of Uranium Deposition in the Bull Canyon Area, Southwestern Colorado.

Tables from the Dolores River District

A report discussing 28 claims contained in the Greagor group, owned by the J.R. Simplot Company.

Discussing a geologic reconnaissance of the northwestern White River Plateau, in Rio Blanco and Garfield counties, Colorado.

A study made of the joint patterns in four different formations exposed in Bull Canyon, and of favorable and unfavorable ground in the upper ore-bearing sandstone unit of the Salt Was member of the Jurassic Morrison formation.

Discussing the geologic setting of the Foothills Mine, Idledale District, Jefferson County, Colorado

Discussing the geology of uranium deposits in the Cochetopa District, in Saguache. County, Colorado

A report on the SOM-vanadium occurrences of the Huerfano Park District.