From outline: The present paper gives a detailed account of the glaciation of the Snowy mountains and of the upper valleys of the Yellowstone, whose deposits show an unusual phase of alpine glaciation. The evidence thus far gathered shows that a large body of ice, originating in the ice sheets of the Yellowstone National Park, pushed northward, filling the upper valleys of the Yellowstone and extending down that stream 36 miles north of the park boundary.

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.

From introduction: The Three Forks sheet of Montana includes the area lying between the parallels of 450 and 460, and extending from longitude 111 to 1120. The three forks of the Missouri river unite in the north central portion of this area about 5 miles south of the northern line of the map.

From preface: This memoir is a general study of the region described, and not a detailed report. The field work upon which it is based formed a part of the work of mapping the areal geology of the Little Belt Mountains sheet of the Geological Survey. The topographic map, made in 1882 by the Northern Transcontinental Survey, is too small in scale and too general in character to warrant more detailed work; but as the facts obtained are of interest, and the region is one of economic importance, it has been considered worthy of a special treatment.

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

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

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: 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.

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: The detailed information concerning the coal deposits of the Ashland field set forth in this report has been obtained in the course of an investigation that has been conducted both as a part of the United States Geological Survey's general systematic study of western coal lands and as an aid in the administration of the public lands. With the information obtained on the location of outcrops, the number, distribution, and thickness of coal beds, the accessibility of the coal, and the thickness of the overburden, the public lands of the region are classified as to their coal value; coal-bearing lands are differentiated from noncoal-bearing lands; and the administration of the coal-land leasing law is facilitated.

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

From introduction: This report contains information concerning the geology of Big Horn County and the Crow Indian Reservation and their resources in ground water, coal, oil, and gas. These facts were collected in the course of studies for about a dozen field projects, which ranged in character from reconnaissance studies of large areas to very detailed mapping of certain tracts to show the occurrence of oil and gas. Consequently, the information at hand, either as to the geology or the resources, is not equally complete and definite for all parts.

From abstract: This paper gives the results of a resurvey of certain areas in Montana to which renewed interest has been directed by the development recently of a market for crude phosphate rock in British Columbia, nearby.

From abstract: The Richey-Lambert coal field is an area of about 900 square miles in Richland and Dawson Counties, eastern Montana, along the divide between the Missouri and Yellowstone Rivers. In this region only flat-lying continental rocks occur near the surface. About 300 feet of the Lebo shale member and about 930 feet of the coal-bearing Tongue River member of the Fort Union formation, of Eocene age, are exposed in the area. Deposits of terrace gravel at two levels in the field are tentatively correlated with the gravel on the Cypress Hills, Saskatchewan, which has been assigned to the Oligocene by the Canada Geological Survey, and with the Flaxville gravel, of upper Miocene or Pliocene age.

From abstract: The Rosebud coal field, named from Rosebud Creek and the village of Rosebud, includes an area of about 1,050 square miles and forms a very small part of the subbituminous and lignite coal fields of eastern Montana and Wyoming and the western part of the Dakotas. It is an irregularly bounded tract lying south of the Yellowstone River in eastern Rosebud County and western Custer County and measures 50 miles from east to west and 28 miles from north to south. It adjoins the Forsyth coal field, on the west, the Ashland coal field, on the south, and the Miles City coal field, in part, on the north.

From abstract: This report describes a rectangular area of about 2,600 square miles in Chouteau, Hill, and Liberty Counties, Mont., adjacent to the international boundary. The area is a portion of the Missouri Plateau, a section of the Great Plains province, and lies between the Highwood Mountains, Bearpaw Mountains, and Sweetgrass Hills, of north-central Montana. The southern part of the area is drained by the Missouri River and its tributary Marias River, but the northern part is drained by the Milk River. These streams are trenched in narrow valleys several hundred feet deep. The land surface between them is a rolling plain interrupted by very broad, shallow valleys that probably were eroded during the Pleistocene epoch by large streams whose courses were doubtless diverted from time to time by the continental glaciers. These valleys are now occupied only by very small creeks.

From introduction: This report details the results of a geological survey of the Libby Quadrangle, Montana.

Report discussing investigation of the relation of uranium and phosphate in the Phosphoria formation and its close stratigraphic equivalents.

From abstract: A reconnaissance for sources of radioactive material in North Dakota and eastern Montana was made in 1948. This reconnaissance was followed by a more detailed survey of parts of Golden Valley and Slope counties, southwestern North Dakota, in June 1949. The radioactivity of representative sections of all formations known to be exposed in the area and of three manganiferous spring deposits was determined with portable Geiger-Mueller counters. At 86 localities 82 samples were taken of these formations and also of 10 ground and surface waters.

Abstract: Secondary minerals of the uranite group occur in dense quartz veins and in altered aplitic granite along and near the crest of the east-trending ridge about one mile west of Clancy, Montana. Brief examination suggests that the radioactive minerals are erratically distributed, but a more thorough study of the area will be made by the Geological Survey during the coming field season.

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 abstract: The origin of the gneissic rocks on the eastern border of the Idaho batholith in the Bitterroot Range, near Hamilton, Mont., has long been in dispute. Lindgren regarded these rocks as the product of stresses related to a normal fault along the front of the range with an eastward dip of about 150. He thought both the hanging wall and the footwall had moved, with a total displacement along the fault plane of at least 20,000 feet. The faulting was believed to have been so recent as to be a major factor in the present topography. Langton appears to accept the concept of faulting but to regard the gneissic rocks as formed much earlier from a granitic rock that was more silicic and older than the Idaho batholith.

A report regarding geology of the area adjacent to the free enterprise uranium-silver mine in the Boulder District, Jefferson County, Montana.

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