This paper provides an account of a series of beds embraced within the Laramie and covering the greater part of the state of Montana east of the Rocky mountains.

A report about the Duck Creek Pass quadrangle which forms a large part of the bedrock of western Montana and adjoins other areas in which geologic studies are already completed or in progress.

A report which includes 200,000 square miles in the southern part of the Williston basin of North Dakota, South Dakota, and Montana. The Devonian rocks consist mostly of marine carbonate, evaporite, and shale beds.

A report which compares 20,000 feet of Belt rocks in the Mission Mountains Primitive Area in Montana with 40,000 feet of Belt rocks in the Pend Oreille area in Idaho and Montana.

A report about phosphates found in the Permian Phosphoria formation of the Rocky Mountains. This area constitutes one of the worlds largest reserves of phosphate.

A report about the Clark Fork quadrangle which is underlain by more than 38,000 feet of low-grade metasedimentary rocks of the Precambrian Belt series. The quadrangle has both metallic and nonmetallic mineral deposits of considerable value.

A report about gold mineralization at the Golden Sunlight breccia pipe, southwestern Montana, is related to emplacement of Late Cretaceous alkali-calcic rhyolite and subsequent collapse of the Belt Supergroup wallrock and rhyolite in the pipe.

From abstract: Uranium minerals and radioactivity anomalies occur in many silver lead veins and chalcedony veins and vein zones in the Boulder batholith of southwestern Montana.

From introduction: A tectonic map for the northern part of the Cordilleran Foreland was compiled to aid in establishing the geologic setting of uranium deposits within the region, and to determine what relationships, if any, exist between the distribution of uranium deposits and localities, and the regional tectonic pattern (Osterwald, 1955). The relationships might suggest new areas favorable for the discovery of uranium deposits in the Cordilleran Foreland as well as in other areas with similar tectonic history. The map will show the distribution of crest lines and troughs of folds, faults, uranium deposits and localities, and areas of volcanic activity. Outcrop areas of Precambrian and post-Eocene rocks are shown to designate the relative age of structures. Where possible the Precambrian rocks are subdivided into structural types, so that their influence on younger deformations may be inferred. The map of eastern Montana is one of a series being prepared before the final map is assembled (fig. 1.).

From abstract: Geologic settings are recognized in central and eastern Montana and in a few places in southwestern Montana that elsewhere are similar to the settings for the occurrence of uranium deposits. Several specific areas in Montana seem favorable for the occurrence of uranium.

Abstract: Anomalous radioactivity and uranium minerals have been found on the dumps of the Comet, Gray Eagle, and Silver Hill mines situated along the Comet-Gray Eagle shear zone. The shear zone is from 50 to 200 feet in width and has been traced 5 1/2 miles. The Gray Eagle mine is currently being reopened but no underground work, with the exception of a few shallow shafts and adits, has been done between the Gray Eagle and Comet mines. Because of the high U3 08 content of the samples from the Comet and Gray Eagle dumps, it is recommended that a minimum of four diamond drill holes totaling 3, 000 feet be drilled by AEC between the two mines to intersect the shear zone 300 to 500 feet below the surface. This drilling should be made contingent upon the results of the Gray Eagle exploration.

From abstract: A reconnaissance to determine the uranium content of granitic rocks in the western states was made during parts of October and November 1951. The paucity of our knowledge of the granitic rocks that are most likely to contain significant quantities of uranium has prevented all but a very general isolation of areas or types of granitic rocks for reconnaissance examination.

From abstract: Nine uranium deposits occur in a small area west of Clancey, Jefferson County, Mont. These deposits are all in or near silicified fracture zones in quartz monzonite and related rocks of the Boulder batholith. The deposits contain pockets of uranium minerals in cavities in brecciated well-silicified rock. The primary uranium mineral pitchblende has been found in one pod. Secondary uranium minerals occur as fracture linings and in pore spaces in and adjacent to the silicified zones.

From introduction: This report on the geology of the Powder River Basin is one of a series of reports by the Geological Survey on sedimentary basins in the United States.

From introduction: This report evaluates four possible types of subsurface reservoirs for radioactive wastes in the Williston basin.

This is a report on the physiography and glacial geology of eastern Montana and adjacent areas.

From introduction: The main purpose of the field investigations on which this paper is based was to determine the structure of the mountains. The geologic formations were therefore studied, and sufficient data were obtained to construct a combined areal and structural map.

From introduction: acknowledgements.-The Forsyth field was examined to collect data upon which to classify the public land included in it with regard to its value as coal land. The geologic mapping was done with the plane table and telescopic alidade, and all locations were tied to land corners.

From introduction: This report is a guide to the geology and scenery of Glacier National Park.

From introduction: This is a progress report on regional stratigraphic and paleontologic studies of the Upper Cretaceous Montana Group and equivalent rocks in the northern part of the western interior of the United States. It presents preliminary data on the positions of strandlines during a 14-m.y. (million year) span of the Late Cretaceous as well as our interpretations of the geologic history of this period.

From introduction: The discovery of oil near Kevin, Mont., in March, 1922, gave prominence to the Sweetgrass arch, which is a large structural uplift somewhat similar in size and degree of folding to the Cincinnati arch. Most of the development so far attempted on this fold has been on the Kevin-Sunburst dome, a bulge upon the crest of the arch just south of the Canadian boundary. The dome covers about 16 townships, is nearly circular in outline, and has very low dips away from its highest point in all directions. Within the last five years (1923-1927) about 1,500 wells have been drilled upon it, over 880 of which are rated as productive. Since May, 1925, the field has stood second in production in the Rocky Mountain States being exceeded only by Salt Creek.

A collection of writings on the shorter contributions to general geology.

From introduction: This report details the reconnaissance for uraniferous lignites in North Dakota, South Dakota, Montana, and Wyoming during 1948 and 1949.

From transmittal letter: This report contains the results of radiometric examinations of 39 mines and prospects, and a detailed description of the properties examined.