The Panther Canyon Formation was named for exposures at the head of Panther Canyon between Grass and Pumpernickel Valleys, in the southern Sonoma Range, Pershing County (Ferguson and others, 1951).

No fossils are reported from the Panther Canyon Formation. In the Shoshone Range, it rests unconformably on the Late Pennsylvanian to Early Permian Antler Peak Limestone and Havallah Formation (Stewart and McKee, 1977). It unconformably overlies the Favret Formation of Middle Triassic (early Ansian to early Ladninian) age in the New Pass Range (Muller and others, 1951). These relationships suggest a Triassic age for the formation.

The Panther Canyon Formation is composed of impure massive pinkish to gray dolomite and limestone, interbedded with well sorted, pinkish weathering, calcareous sandstone which grades laterally and vertically into reddish mudstone or shale. Well-bedded, green and red siltstones, and gray pebble to boulder conglomerate are locally present. The conglomerates contain chert, quartzite and minor limestone, sandstone, and greenstone in a calcareous sandy matrix (Ferguson and others, 1951; Gilluly and Gates, 1965).

Stewart and McKee (1977) report that massive dolomite and limestone are dominant in the middle portion of the formation, with coarse clastics concentrated in the upper and lower portions of the formation. In describing the China Mountain Formation (now considered the Panther Canyon Formation) in the Shoshone Range, Gilluly and Gates (1965) described the lower 200 to 250 feet of the formation as limestone, mudstone, shale, and siltstone giving way upward to 200 to 250 feet of conglomerate, some of which they considered a fanglomerate, and calcareous yellowish sandstone. The formation apparently becomes coarser grained and more clastic upwards.

The Panther Canyon Formation is 100-300 feet thick at the type section in the Sonoma Range (Ferguson and others, 1951) and 700 feet thick in the New Pass Range to the west (Stewart and McKee, 1977). It is 400-500 feet thick in the structurally complicated Shoshone Range (Gilluly and Gates, 1965).

The Panther Canyon Formation is exposed in the Mount Lewis area of the Shoshone Range, and to the west of the evaluation area in the northern Fish Creek Mountains, and Sonoma and New Pass Ranges.

The depositional setting of the Panther Canyon Formation is poorly understood. Overall the unit coarsens upwards from limestone and dolomite to sandstones and chert-pebble conglomerate. This upward coarsening may represent shallowing upwards within a deltaic depositional environment. The Panther Canyon depositionally overlaps the Golconda allochthon in the Shoshone Range (Nichols and Silberling, 1977).