Trout Water: A Year on the Au Sable

"Josh Greenberg is my kind of nature writer."—The Wall Street Journal

It's the beginning of trout fishing season, and Josh Greenberg — proprietor of one of the nation’s most famous fishing outfitters, on America's most iconic trout-fishing stream, the Au Sable River in Michigan —is standing in the Au Sable at dusk when he gets the call that a dear fishing buddy has died.

The solace he takes from fishing — from reading the movement of the river water, studying the play of the light, and rely...