Named Reclamation group. These rocks were previously assigned to Division V of Hartville formation [not used in this report] in earlier reports. Recognized in Hartville uplift area, Wyoming, and Hot Springs area, South Dakota, on the Chadron arch. Composed of alternating beds of dark-gray and maroon, mottled dense limestone; and dark maroon and green polka dot, thin bedded shale with limestone nodules. Limestone beds are fossiliferous. Ranges from 72 to 87 feet thick. Overlies Fairbank formation (new); underlies Roundtop group (new). Correlates with part of Cherokee group of Des Moines age. Age is Pennsylvanian. Report includes measured sections.

Type locality: Reclamation Hill, sec. 27, T. 27 N., R. 66 W., Platte Co., WY, in the Denver basin. Named from Reclamation Hill.

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

Combined with overlying Roundtop group to form a subdivision of Hartville formation in the subsurface, along the east side of Powder River basin in Niobrara, Weston, Crook, and Campbell Counties, Wyoming. /Reclamation-Roundtop groups overlie Fairbank formation and underlie /Meek-Wendover and Hayden groups, all considered subdivisions of the Hartville formation. Correlated with Amsden formation in the Bighorn Mountains, Wyoming. Age is Early Pennsylvanian (Atokan).
[The use of a hyphen between undifferentiated [groups] has not been considered proper notation since 1933 (see CSN, Art. 13a, p. 437-438). Where the [groups] have not been separated in the field, it is considered proper notation to add the word "and", "undifferentiated", "included", etc.; and list [groups] in order of age (youngest first).]

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

Used in formational sense in Williston basin. Consists of argillaceous limestone interbedded with thin, red and green shales. Mapped in subsurface, in combination with overlying Roundtop and underlying Fairbank(?) [formation]. Formerly included near the top of Amsden formation by the North Dakota Geological Society (1954, Stratigraphy of the Williston basin). Age is probably Early Pennsylvanian (Atokan); see correlation chart (table 2, p. 151).

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