1791 W. L. Bowles African in 16 Or rushing down the mountain-slope O'ertake the nimble Antelope.
1841 H. D. Thoreau 4 Mar. (1981) I. 278 Their way is a mountain slope—a river valley's course.
1991 17 June 81/2 Plants, mosses, and trees are..thick on the vertiginous mountain slopes.