Named as the basal member of the Skinner Ranch Formation (new). Type section designated as the section 1.25 mi S 25 deg W of Peak 5300 in Lenox Hills, Altuda 15 min quad, Glass Mountains, Brewster Co, TX in the Permian basin. Is 98 ft thick at type where it is described in the measured section as (ascending order): massive ledge-forming boulder conglomerate of limestone boulders up to 1 ft long, and scattered chert and quartz pebbles; calcarenite and fine-grained sandstone; chert pebble limestone conglomerate; yellow platy shale with 6 in detrital limestone 1.5 ft below top; massive calcarenite; yellow limy shale; cobbly limestone; gray calcarenite with small bioherm near top. Overlies Lenox Hills Formation. Underlies Poplar Tank Member (new) of Skinner Ranch. Formerly mapped as Hess Formation. Ranges from 40 to 98 ft thick in Lenox Hills. Extends across south base of Lenox Hills to east side of Hill 5021 where the Poplar Tank Member tongues out into the Skinner Ranch, the Decie Ranch and Sullivan Peak (new) Members of the Skinner Ranch merge, and the Skinner Ranch is undivided. Fossiliferous (fusulinids). Of Leonardian, Early Permian age. Cross section.

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