From introduction: This report describes the results of an investigation in which three computer models were used to evaluate different levels of the proposed reservoir development. One model simulated streamflow conditions with alternative multireservoir configurations; a second model simulated the dissolved-solids concentrations at various locations in the basin; and a third model used streamflows and dissolved solids concentrations to simulate the water-quality conditions within certain proposed reservoirs. This study was designed to demonstrate the application of computer-modeling techniques in evaluating impacts of proposed reservoirs.

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.

Discussing wall-rock control of certain pitchblende deposits in Golden Gate Canyon, Jefferson County, Colorado

Report discussing a geological study of the Union Pacific prospect near the Golden Canyon in Jefferson County, Colorado.

From abstract: Pitchblende, associated with base-metal sulfides, has been found at eight localities in the northern part of Jefferson County, Colo., in shear zones that cut pre-Cambrian metamorphic and igneous rocks, chiefly hornblende gneiss, biotite schist, and granite pegmatite. The pitchblende deposits, with one exception, are in major shear zones that contain vein-like bodies of carbonate-rich breccia. The breccia bodies range from 1 to 5 feet in thickness and are related probably to the Laramide faults, or "breccia reefs" of similar trend, mapped by Lovering and Goddard (1950).

From abstract: because of the increased demands for water in eastern Colorado, principally in the urbanizing Denver metropolitan area, increased diversions of water from Dillon Reservoir are planned. Estimates of end-of-month storage in Dillon Reservoir, assuming the reservoir was in place and 131,000 acre-feet of water were diverted from the reservoir each year, were reconstructed by mass balance for the 1931-77 water years. Based on the analysis, the annual maximum end-of-month drawdown below the elevation at full storage would have been 171 feet.

Abstract: San Miguel bench includes about 4 square miles in the southern part of T. 48 N., R. 17 W., New Mexico principal meridian, Montrose County, Colorado. Production of carnotite ore from the area has been about 15, 000 short tons having an estimated average graderof 0. 31 percent U3O8,and 1. 6 percent V2 05 Nearly all of the carnotite deposits occur in a single-continuous sandstone bed near the top of the Salt Wash member of the Jurassic Morrison formation. These deposits consist chiefly of sandstone impregnated with uranium- and vanadium-bearing minerals. They are irregular tabular-shaped masses ranging in size from a few short tons to 30, 000 short tons or more of minable carnotite ore. During the period November 27, 1951, to April 17, 1953, the U. S. Geological Survey drilled 309 holes totaling 92, 194 feet on the San Miguel bench. Reserves total about 43, 000 short tons of material 1 foot or more thick and contain 0,.10 percent or more U30 or 1. 0 percent or more V205. Of these reserves 3, 300 short tons occur in private land. These reserves are in ten deposits found by Geological Survey drilling. Potential reserves (reserves based on geologic evidence …

Report discussing the San Miguel bench and the production of carnotite from deposits consisting of sandstone with uranium- and vanadium-bearing minerals.

A report discussing an exploration of the san Miguel Bench

This report tracks and analyses the annual sediment yield for the Yampa River basin in Colorado and Wyoming. It includes maps, tables, and graphs.

Report discussing a study on the connection between carbonate content of samples from the Salt Wash member of the Morrison formation and the lithology and vanadium-uranium deposits in the area.

From abstract: In the Sawatch, Mosquito and Front Ranges of central Colorado and the Sangre de Cristo Mountains of south-central Colorado, Tournaisian beds of the Mississippian Leadville Limestone overlie rocks of Early Mississippian and Late Devonian age. In the Sangre de Cristo Mountains in north-central New Mexico, the oldest beds are the Tournaisian (zone 9) Espiritu Santo Formation. In west-central New Mexico, in the Magdalena, Lemitar, and Ladron Mountains, the Kelly Limestone of Tournaisian and Visean age rests unconformably on Proterozoic metamorphic and igneous rocks. This report examines the stratigraphy of this area.

From introduction to each respective report: Report J summarizes the results of several studies concerning the stratigraphy and sedimentology of uppermost Jurassic to lowermost Upper Cretaceous rocks in the San Juan basin and adjacent areas. Report K describes using X-ray diffraction techniques to determine the occurrence and distribution of clay minerals in the upper part of the Brushy Basin Member and in the Burro Canyon Formation in the Four Corners area.

The following report covers investigation work done on the distribution of thick deposits of salt that had occurred in the Paradox member of the Hermosa formation of Pennsylvanian age in an area nearly 12,000 square miles of southwestern Colorado and southeastern Utah.

From abstract: Coal and carbonaceous shale of the Dakota formation of Cretaceous age were examined for radioactivity in the Colorado Plateau of southwestern Colorado and northwestern New Mexico during the summer of 1953.

A report regarding the distribution and thickness of salt in the paradox basin of southeastern colorado and southeastern Utah. This report concerns work done on behalf of the Division of research of the U.S. Atomic Energy Commission.

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

A report about minerals fuels and geologies located in parts of the Routt and Moffat counties, Colorado.

This report studies the geology of mineral deposits in Mount Harris, Pilot Knob, Elkhead Creek, and Daton Peek quadrangles in northwestern Colorado.

This report presents the findings of the analyses made for a fifty-eight mile stretch along the Yampa River in Colorado. It contains maps, graphs, and tables.

From purpose and scope: The primary purpose of the study was to aid in evaluating the waste-load assimilative capacity of the study reach for a minimum mean 7-day low flow and 10-year recurrence interval. The results of this analysis will provide planners and managers in Routt County with information for determining the waste-load capacities of the study reach for possible design and operational alternatives of future wastewater-treatment plants.

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.

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).