Loc. 58 French ranch localities. Sections measured in SW-facing bluffs in amphitheater-like end of spur in and ESE of center SW1/4, sec. 31, T. 15 N., R. 23 E., Lantry NE gund. Dewey Co. Actually on tribal land, but French leases for cattle; access thru French ranch. Section 1. Measuring up from big bentonite 1.6 Bentonite, light olive-green, soapy. contains siltly cone-in-cone cones. 2.0 Shale, gray, fissile, with silt laminze scattered throughout, some Fe yellow brown to brown stain on bedding & fracture surfaces. About 2' from top- Febru ls cone barrow, 8" diam. 3.0.1 Javosite bend- light gray, soft. silt masses with javosite rinds. 4. 18.0 Clay, silty, shely in lower 2 feet ± and some shaly layers locally but mostly blocky fracturing gray to light gray silty clay with silt blebs and some laminac fracture surfaces weather purple slope weathrs lite gray. 5. 3.0 to ? Clay, as above, javosite band at base, at 1.3-2.3 above base.