Named for King Peak, southwest part of map. Extends northwest of King Peak and about 1 mi north-northeast toward Copper Creek and along Bridle Creek, southwest part of Bagdad area, Yavapai Co, AZ in Southwestern Basin-and-Range region. No type locality designated. Is a fine-grained non-porphyritic intrusive rhyolite containing quartz and feldspar. Generally massive, white and sugary on unweathered surfaces, and brown to tan locally. Has inclusions of volcanics from Bridle formation. Alternating layers, averaging 20 ft in width parallel bedding structure of Bridle, suggesting bed-by-bed intrusion of the rhyolite. Main mass near Copper King mine probably intruded along a fault. Outcrop pattern suggests intrusion after deposition of the older Yavapai series. Of pre-Cambrian age. Geologic map.

Source: GNU records (USGS DDS-6; Denver GNULEX).