The Triangle A pegmatite is 4 miles southeast of Custer in the SW 1/4, sec. 34, T. 3 S., R. 5 E., Custer County, S. Dak. It may be reached from Custer by a gravel road 2.4 miles long that leaves U.S. Highway 16A at a point 3.2 miles east of Custer.

January 1, 1955

Geologic map of the Walsenburg area, Huerfano County, Colorado

No abstract available.

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Bentonite deposits of the northern Black Hills district, Montana, Wyoming, and South Dakota

Davis Mesa quadrangle, Colorado

Geologic and radiometric maps of the McKinley Mountain area, Wet Mountains, Colorado

Geologic and structure map of the Sussex and Meadow Creek oilfields and vicinity, Johnson and Natrona Counties, Wyoming

Geologic map of Canal Zone and adjoining parts of Panama

Geologic map of Cave Hills and Table Mountain area, Harding County, South Dakota

Geologic map of the Bar H area, Slim Buttes, Harding County, South Dakota

Geologic map of the Du Noir area, Fremont County, Wyoming

Geologic map of the Slim Buttes area, Harding County, South Dakota

Geologic map of the southern part of the Slim Buttes area, Harding County, South Dakota

Geologic map of the Triangle A pegmatite, Custer County, South Dakota

Geologic map of the Walsenburg area, Huerfano County, Colorado

U.S. Geological Survey

U.S. Department of the Interior