Post route map of the territory of Dakota with adjacent parts of Montana, Wyoming, Nebraska, Iowa and Minnesota, and portions of the Dominion of Canada /

Dated 1879.
"The service on this diagram brought up to date of March 1st, 1881."
Originally printed 2 maps 73 x 51 cm. on sheets 76 x 54 cm., sheets joined vertically to form 1 map.
Prime meridian: Washington, D.C.
Available also through the Library of Congress Web site as a raster image.
Includes explanation of mail service.