Named after Horned Toad Hills, type locality about 4 mi northwest of Mojave, Mojave 15' quad (E/2 sec.33 T32S R33E, M.D., and NE/4 sec.35 and NW/4 sec.36 T12N R13W, S.B.) Kern Co, CA. Crops out in low southeast foothills of Tehachapi Mountains from Warren Station southwestward about 3 mi. Consists of: (1) lower member (900 ft thick) of gray-white arkosic sands, siltstone and conglomerate; (2) middle member (75 ft thick) of indurated green muddy sandstone with layers of white caliche; and (3) upper member (80 ft thick) of gray gypsiferous clay. Overlies quartz monzonite and intrusive quartz latite. Unconformably underlies sand, siltstone and fanglomerate of probable Pleistocene(?) age. Has yielded mammalian fossils indicating early or middle Pliocene age (Merriam, 1914).

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

Type section designated from base of Horned Toad Formation about 7000 ft S 70 deg W of Warren railway camp south-southeast 1 mi to top of unit, Horned Toad Hills, 4 mi northwest of Mojave, Mojave 15' quad, Kern Co, CA. Vertebrate fossils collected 2 mi southwest of Warren railway station, presumably from middle member indicate middle Pliocene (late Hemphillian) age (R.H. Tedford, D.E. Savage, written commun. Nov.23, 1960).

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

Age of Horned Toad Formation, previously considered middle Pliocene is here considered late Miocene on basis of late Miocene age assigned to its late Hemphillian mammalian faunas.

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