Loc. 275, High, west-facing cut of Standing Cloud Cr. in SE 1/4, NW 1/4, SW 1/4, NW 1/4, sec.8, T18 N. R. 23E Black Horse SE. qd., Corson Co, S.D. Measuring up from creek bottom. 1) 10.3 Sand, fq., clayey, gray, some blobs of gray clay. In basal foot discontinuous layer of hard sandy gray conchs and, for about 2 ft above, a few scat. flat conchs of same type and loose shells in matrix. Basal Conchs A 4660 - P. linguiformis Conc 1.0' above basal conchs. A 4661 Mzora Loose fossils include Teneedia, Fusus, in 2 or 3' above the basal layer. A 4662 - parts of a second Mztora- Tullina concraction Concractions and matrix both have a great amount of wood - much of it black, locally having clams in large chunks wood in conchs in lower level. 2) 13.0 Sand, fq, wezths light yellowish orange, few clay blobs, concs, small in lower 2 to 3' chiefly P. linguiformis Wezths massive shows no bedding structure. (Single conch base A 4663) 3) 2.0 As above, some scattered Teneedia valves appear. Massive, could add to interval # 18