Most settlers and-others who have recently visited the mountains south of Yellowstone Park know “the Gros Ventre slide.” Its wide reputation is due largely to the fact that for several years the landslide made communication between the upper and lower parts of the valley of the Gros Ventre River difficult and uncertain. Although the name which heads this paper is the one generally used in the vicinity, it is not quite satisfactory to the geologist, because it suggests the sudden plunge and immediate quiescence which attend landslides and avalanches in general. As the facts presented in these pages indicate, the term “earth-flow,” or even “earth-glacier,” would be more appropriate in this case.
The position of the slide may be found by consulting the southwest part of the Mount Leidy, Wyoming, topographic sheet, published by the United States Geological Survey. It occupies the valley of Lake Creek, one of the . . .