The great Michigan football coach Fielding Yost had a theory for the nickname, which he wrote about in 1944. Yost felt the nickname concerned the trading of wolverine pelts in Sault Ste. Marie for many years. The trading station served as an exchange between the Indians, other trappers and fur traders. Because many of the furs were wolverine pelts, traders may have referred to them as "Michigan wolverines," leading to the state nickname and ultimately to the University of Michigan symbol.