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- 29 - Area South of Crystal River and Opposite the Mudf10w Fan (4) Gaskill's geologic map indicates that the area south of the Cry- stal River in the vicinity of Marble is composed of the same Cretaceous shales and sandstones that were described on Gallo Bluff (plate 2). Slopes of this area are in the range of 40% to 100%. Both photographic and field observation indicate that the western part of this slope is an area of long standing and still active snow avalanching (4a, plate 1; figures 1, 4, 14). There are seven avalanche tracks across the area, and photo studies indicate that the accumulation areas have enlarged by erosion considerably since 1945. At the foot of each avalanche chute, there is a talus of fresh rock debris. In view of the steepness, the nature of the bedrock and the active avalanching and rockfall, these areas do not appear to be suitable for development. The central part of the area south of Crystal River (which is di- rectly opposite the old marble works) is also very steep except for a large and fairly recent landslide mass (4b, plate 1) which has locally deflected the course of the river northward. There are also large ac- cumulation areas and avalanche tracks above the landslide mass. These avalanches do not at the present time appear to be as active as those to the west, but the historic record describes many damaging avalanches which affected the marble works until a protective dike of waste marble was built. We feel that this part of the area also has many serious problems which would have to be resolved before construction of any kind is advisable. The eastern part of the area south of Crystal River looks somewhat more favorable, but there are still several reasons for carefully con- sidering any construction in the area. The geologic map (plate 2),