Every year since 1985, envelopes with letters prepared especially for this event, are gathered, loaded onto sleds and several dog teams haul it to Rosseau, Ontario, 17 km through the bush on groomed trails.

Teams gather and leave from the Village of Humphrey, Ontario, on Highway 141, to the cheers and good wishes from the many spectators and friends as the teams disappear in the bush on their way to the Rosseau Post Office to be received by the Post Mistress.

The sledvelopes are hand stamped, a very old method of cancelling mail. These "sledvelopes" have become collector items all over the world.