Map showing geochemical summary for the Bald Rock and Middle Fork Feather River Roadless Areas, Butte and Plumas counties, California
The Bald Rock Roadless Area consists of 3,850 acres in Butte County, Calif. The Middle Rock Feather River Roadless Area consists of 29,300 acres ub Butte and Plumas Counties, Calif. Both roadless areas are in the Plumas National Forest and are on the west slope of the northern Sierra Nevada southwest of Quincy, Calif. (fig. 1). The two roadless areas are alined along the Middle Fork of the Feather River where they include the narrow canyon bottoms and precipitous sidewalls of the Middle Fork and several tributary drainages. Altitudes range from 800 ft in the canyon of the Middle Fork to approximately 6,600 ft at the northwest corner of the map area. The geology of the roadless areas has been briefly summarized by Sorenson and Pietropaoll (1982). This paper summarizes and interprets the semiquantitative emission spectrographic analyses of 106 rock sample and 165 samples of nonmagnetics heavy-mineral stream-sediment concentrates from the Blad Rock and Middle Fork Feather River Roadless Area (Sorenson and others, 1982).