AIN 50-37 (1) Trench by Colo. Sch. Mines exposes section from Lyons to Pierre through Golden fault. Details of this fault can be seen— Sketch of S wall trench obscure concretion with Baculites SS+ shale SS+ gouge zone SS+ grey shale base of cut 38°W probably all the 3rd glaciation clay Greatest dip meets on fault is 38°, locally less than 50° Sketch N wall of trench Note: dry 25°W obsc. SS+ shale SS+ gouge zone SS+ grey shale base of cut (2) This pit shows 3rd Glaciation structure (+ Glen-Lyttle contact - possibly with fault) and above it the 3rd Glaciation shale—[has its lower bentonite Big question is whether this is the fault and shale Pierce, or whether a subsidiary fault and shale Graneros. Correction—shale is Pierce, concretion containing Baculites found in place in position indicated in sketch above