Drift about the St Mary R. Stones of Laurentian origin begin to appear among the drift, which however still remains chiefly of Rocky Mt rocks.

Aug 31. Leave camp 6 A.M. Ride down to line & follow it Eastward with Ashe. Strike 2nd branch Milk R & follow it up to trail about 3 miles examining sections. Afternoon made about 12 miles. Left trail & went about a mile S. to camp on a bend of the first Branch where good feed. Examine sections which near those formerly examined which contained vertebrate bones. The river much smaller than when last seen.

Geol. On the second branch. Sections show bluish-grey clays & clay rocks interstratified with sandstones & impure ironstones from the line to the trail. About 3. miles. (Sections near the trail formerly examined & fossils procured from them) Layers nearly horizontal & in marked contrast with disturbed state of beds W. of St. Mary R.

Exposures on first Branch at camp examined for fossils. A good many fragments of large bones but but [Dawson did 2x] none perfect. Sandstones & bluish & greenish grey clay rocks clays & sandy clays. These colours appear characteristic of the lowest tertiary? [Dawson's?] beds.