Named as a member of Bullion Canyon Volcanics for exposures in cliffs along Three Creeks, a tributary of Clear Creek, Sevier Co, UT on the Wasatch uplift. Occurs within Bullion Canyon and Dry Hollow Formation (abandoned). Is widespread in northern Treshar Mountains and Pavant Range (Millard Co, UT in the Great Basin). In Clear Creek area was called Clear Creek Tuff Member of Dry Hollow, a name preempted. Is a multiple ash flow compound cooling unit. Reference section designated in the Narrows of Clear Creek Canyon. Is more than 600 m thick. Overlies intermediate-composition lava flows and inter-layered ash-flow tuffs. Is older than the Delano Peak Tuff Member (redefined) of the Bullion Canyon. Has isotopic ages of 27.0 +/-1.2 m.y. from a welded tuff on south side of Bullion Canyon and this age is in close agreement with a K-Ar age of 27.5 +/-0.4 for biotite in the lower part of the member on Clear Creek. Assigned to the Oligocene.

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

Is a member of the Oligocene Bullion Canyon Volcanics that replaces use of name Wallaces Peak Tuff Member (abandoned in this report) of Needles Range Formation in southwest UT in the Great Basin province. Both Wallaces Peak and Three Creeks had similar lithology and mineralogy, normal magnetic polarity, same general age, and same source (east of Indian Peak caldera).

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