During the months of June and July, 1904, the writer, under the direction of Dr William H. Dall, made a reconnaissance of the coast of the Olympic peninsula, Washington, from Port Angeles, on the south shore of the strait of Juan de Fuca, to Grays harbor, on the Pacific. Chester W. Washburne, of Eugene, Oregon, and Russell G. Wayland, of Seattle, assisted in the work. The trip was primarily undertaken for the purpose of collecting the fossils and working out the stratigraphy of the Tertiary rocks of the region; in addition to this, however, notes were made on the other important geologic features of the country traversed. This paper embodies an outline of the results of the reconnaissance. Mr J. S. Diller, of the U. S. Geological Survey, visited the region of Clallam bay in 1892 to investigate the coal deposits there, and Professor Henry Landes and a party . . .