Named as a tongue of the Dinwoody formation probably for exposures (type section) on the Little Medicine Bow River in the Little Flat Top anticline about 8 mi north of town of Medicine Bow on the road from Medicine Bow to Casper, Carbon Co, WY in Greater Green River basin. Is exposed in Rattlesnake Hills, at Alcova, in Freezeout Hills, in Ferris and Seminoe Mountains, and at some localities in Laramie basin. Consists of variegated (tan to gray, olive-green, lavender, maroon, purple), platy, finely laminated, fine-grained, calcareous sandstone, though at some localities, it is nearly a pure limestone. At some places it includes impure gypsum. Has some small muscovite flakes and some glauconite. Its contact with the underlying red shale of the Freezeout tongue (new) of the Chugwater is gradational. Underlies main body of Chugwater formation. Cross section; measured sections. Consists of sandstone and gypsum 20 ft thick along Casper Creek, Rattlesnake Hills; sandstone and gypsum 16.5 ft thick near Alcova, both in Natrona Co, Wind River basin. Is a 10 ft thick limestone near Difficulty in the Freezeout Hills of Carbon Co. Considered Triassic in age.

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

Reassigned as the upper member, of eight members, of the Goose Egg Formation in Carbon and Albany Cos, WY in the Greater Green River basin. Overlies Freezeout Shale Member, newly assigned to the Goose Egg. Underlies Chugwater Formation. Is a thin (5 to 25 ft thick) widespread unit of gypsiferous and argillaceous dolomite or limestone in the northern Laramie Range, Shirley Basin, and Freezeout Hills. Southeast of these localities, the Little Medicine is mostly gypsum and anhydrite. Correlates westward to part of Dinwoody Formation. Early Triassic age. Correlation chart; cross section.

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