The Wolfcamp formation (or the Upper Pennsylvanian) deposited during the late Pennsylvanian through the late Wolfcampian is distributed across the entire Permian Basin.

Stratigraphically, from top to bottom, as the A, B, C, and D (Cline Shale) benches. The Cline Shale (or the Wolfcamp D) east of Midland, Texas underlies ten counties: Fisher, Nolan, Sterling, Coke, Glasscock, Green, Howard, Mitchell, Borden and Scurry. All will rely on hydraulic fracturing.

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The Eastern Shelf is part of the eastern Wolfcamp where depths are shallower but the formation is thicker - three times thicker than on other lease acreage. ​The Strawn formation (Middle Pennsylvanian), a much targeted formation on the Eastern Shelf, is typically found at depths ranging from 4,000 to 6,500 feet. Some horizontal, shallower, adjacent intervals may be found around 7,200 feet featuring productive, historically-developed, low-cost reservoirs; smaller, but high-quality, oil-rich reservoirs.