Reactivated fault scarp at Grayling Creek. Hebgen Lake, Montana Earthquake. 1959.

Album caption: Reactivated fault scarp at Grayling Creek. The 1959 scarp, about 10 feet high, is precisely superimposed upon an older fault scarp of similar height that shows best just southeast of Grayling Creek. A still older and greater displacement produced a moat within which Grayling Creek flowed for a time; the stream cut back the scarp then formed to produce the 60-foot erosional escarpment that parallels the younger structural scarps. Dark areas are cloud shadows. Montana earthquake area, Gallatin County, Montana. August 17, 1959. (Aerial photography by U.S. Forest Service). No index card. Published as Figure 36 in U.S. Geological Survey. Professional Paper 435-I. 1964.