The snow-crust marked by the streams of water

February 2. 

The snow-crust on all hills and knolls is now marked by the streams of water that have flowed down it, like a coarsely combed head; i. e., the unbroken crust is in alternate ridges and furrows from the tops of the hills to the bottoms.

H. D. Thoreau, Journal, February 2, 1857

See February 2, 1854 ("The Cliff Hill is nearly bare on the west side, and you hear the rush of melted snow down its side in one place")