F. D. Haines, Oregon Historical Quarterly (1936)
“ Between December 10, 1812, and January 15, 1813, McKenzie made the trip from Spokane to his post, cached his trade goods, and made his way to Astoria. Under winter conditions, it would be extremely difficult for him to even make the trip from Spokane to Fort Boise in this short time, as the air line distance between the two is more than two hundred sixty miles and much of it would be across mountains covered by many feet of snow. Also, it would not be feasible to send eighty horses across this trail in the spring before the high trails were open. ”
