intermittent in zone 1 to 12 feet above basal lignitic shale. Fauna otherwise is all vertebrate including Myledaphis, dinosaur bones + teeth (amosaur) crocs, turtles, presumed cheyresosaurs, also much water-worn charcoal - sampled to be tested, the usual wood and plant frags. Locally lower lignitic shale is absent - Calpeta-Bullhead-like beds in with Corbicula association at close to Unio horizon. Relationships obscure, (probably recent) Unio sand includes clay pellets, plant frags etc on fresh cut. Unios commonly both valves, some aligned - hinges down. Loc 304 Includes that part of Iron Lightening bedleads north of the E-W bluff of Well Creek on west rim of bedleads in NE cor sec 32 (actually NE 1/4 NE 1/4; E 1/2 NW 1/4 NE 1/4; most of N 1/2, SE 1/4 NE 1/4; 2nd NE cor SW 1/4 NE 1/4) and SE part sec. 29 (actually SE 1/4; 2nd part E 1/2 SW 1/4) T 14N, R 19E, Red Elm NE Quad. Ziebach Co., So Dak. Good exposure of Unio bed in horiz zone of principal draw coming in to 13