The Buckskin Mountain Formation was designated by Fails (1960) for exposures in Sec. 22, T. 33 N., R. 53 E., north of Carlin Canyon and is also exposed 3 miles to the south on Buckskin Mountain from which the name has been taken.

The Buckskin Mountain Formation is Permian (Wolfcampian) in age. It is conformably overlain by the Beacon Flat Formation and conformably overlies the Strathearn Formation at the type section (Fails, 1960). The Buckskin Mountain Formation is probably correlative with the Garden Valley Formation and part of the Carbon Ridge Formation.

The Buckskin Mountain Formation is composed of interbedded light yellow to brown quartzose calcisiltites and gray-brown clean calcisiltite. Minor beds of gray, fine to coarse-grained calcarenite and brown chert beds are present in the unit. In general 5 to 10 foot thick beds of quartzose calcisiltite are separated by 1 to 2 foot thick beds of pure calcisiltite or calcarenites (Fails, 1960).

Along the western flank of the HD Range, Riva (1970) described a sequence of lithologies which he broke into two members and assigned to the Buckskin Mountain Formation. The lower unit disconformably overlies the Quilici Formation and is composed of about 400 to 700 feet of thin-bedded and platy, tan, pink, and purple-weathering siltstone and shale with thin platy limestone interbeds in the lower 300 feet. The upper member is about 600 feet of medium grained, light brown sandstone which is locally silicified and brecciated, and is interbedded with thin platy limestone in the lower 300 feet of the interval. Worm tracks are common in the upper member, and brachiopods, bryozoans, crinoids, pelecypods, and gastropods are present throughout the unit (Riva, 1970). Along the eastern flank of the range the formation forms a thinner unit which consists primarily of tan and olive-gray siltstone and shale interbedded with thin gray limestones (Riva, 1970).

In the Windermere Hills, the Buckskin Mountain Formation is brown-gray, brown-red weathering, platy and flaggy, calcareous quartz siltite with interbedded lenses of medium-bedded quartz-chert arenite as much as 80 feet thick, medium-bedded bioclastic calcisiltite and calcarenite beds up to 10 feet thick, and a few graded rudite beds with subrounded clasts of brown, black, tan and green chert and gray orthoquartzite (Oversby, 1972). Worm tracks and trails are common in the upper portion of the formation. The Buckskin Mountain conformably overlies the Strathearn Formation here which was included with the Carlin Sequence during mapping.

In the northern Leach Mountains the Buckskin Mountain Formation overlies the Diamond Peak Formation and consists of poorly exposed quartz-rich calcareous siltstone and lesser amounts of interbedded limestone (LeCompte, 1978). About 60 percent of the unit is composed of gray and yellowish or reddish-purple, fissile calcareous siltstone. Silty and organic, gray limestone with crinoids, brachiopods, fusulinids, bryozoans and gastropods makes up about 30 to 40 percent of the formation (LeCompte, 1978). In the southern portion of the range the Buckskin Mountain is composed of thin-bedded brown, yellowish and orange, fine-grained quartzose calcareous sandstone, interbedded with gray, thin to thick-bedded, sandy limestone with fragments of brachiopods, bryozoans, and crinoids (Martindale, 1981) . The sandstone locally contains pebble-sized clasts of sand and silt and chert and the limestones locally contain pebble to cobble or boulders of limestone. Parts of the Buckskin Mountain Formation have been removed along a low angle fault between the Buckskin Mountain and overlying Pequop Formation in the southern Leach Mountains.

At the type section near Carlin, the Buckskin Mountain Formation is about 1,200 feet thick, it is about 1,200 feet along the western HD Range and 700 feet along the eastern HD Range (Riva, 1970), 1,500 feet in the Windermere Hills (Oversby, 1972), 3,180 feet in the northern Leach Mountains (LeCompte, 1978) and locally about 590 feet in the southern Leach Range where the upper contact is a fault (Martindale, 1978).

The Buckskin Mountain Formation is exposed near Carlin, in the HD Range, Windermere Hills, and Leach Mountains.

Bissell (1962) suggested that the Buckskin Mountain Formation was a fine-grained clastic facies of the Ferguson Mountain Formation and that the name be abandoned, but later workers including Riva (1970) have disagreed and retained the Buckskin because of its unique lithologic character.

The Buckskin Mountain Formation is probably a eastern facies equivalent of the Carbon Ridge Formation representing a more distal position from the sediment source with deposition under relatively quiet and clear shallow marine conditions. Martindale (1981) suggests that sandy limestones in the Buckskin Mountain Formation in the southern Leach Mountains represent submarine, sediment gravity-flow deposits, and that the calcareous sandstones represent shallow subtidal deposition in water depths of about 150 feet.