Advertising postcard for the Colorado Big Bore M.M.& T. Co. showing a Rocky Mountain pasture with two donkeys ("Rocky Mountain Canaries") and building in the background. Caption on front: ROCKY MOUNTAIN CANARIES. Compliments of The Colorado Big Bore M.M.&T. Co. 95 Main St., West Battle Creek, Mich. Copyrighted by the Western Souvenir Co., Denver, Colo. Agents Wanted.