A naturalist canoes two thousand miles down the Athabasca and Slave rivers to the caribou grounds beyond Great Slave Lake, counting animals, sketching tracks and arguing that the northern herds are larger than anyone believes. Ernest Thompson Seton founded the Woodcraft movement and drew every animal he wrote about. The census of the caribou is the first attempt anyone made. Fifty-eight plates from 1810 to 1925, among them ship portraits by Charles Towne and Joseph Heard, run from icebound barques to a summer evening, matching the river miles and northern waters of the journey.