Formed by the confluence of the Ocmulgee and Oconee Rivers, the Altamaha is the largest free-flowing river on the East Coast and drains its third-largest watershed. It has been designated as one of the Nature Conservancy's seventy-five Last Great Places because of its unique character and rich natural diversity. In evocative photography and elegant prose, Altamaha captures the distinctive beauty of this river and offers a portrait of the man who has become its improbable guardian.

Few people know the Altamaha better than James Holland. Raised in Cochran, Georgia, Holland spent...