This particular Colton map, no. 43, are located in Colton's General Atlas. His atlas contained one hundred and seventy steel plate maps, including this Lake Superior and Northern Michigan map. This print map comes matted in a 20 in. x 16 in. board.
Dimension: 20 in. x 16 in.
Matte window: 14 3/4 in. x 11 3/4 in.
Reference: Karpinski, Louis C. Bibliography of The Printed Maps of Michigan 1804-1880. Michigan Historical Commission. 1931.