“…They were originally termed the "Bozeman lake beds," but most of them are fluviatile rather than lacustrine in origin, and modern work indicates that they are heterogeneous, including deposits of many Tertiary ages, now collectively referred to as the Bozeman Group (Robinson, 1961(Robinson, , p. 1003(Robinson, -1004 (Kelley and Silver, 1952, p. 120-123). The first is a red bouldery deposit with many volcanic clasts, the second a light buff tuffaceous clay.…”