This map was furnished by Chris Cooper who's ancestor submitted an application for a new post office to be called Oshawa near Pryor's Mill (later Heckman's Mill) on the Gasconade River.  The map was to show the location of the "Post Office, as also the roads to the adjoining offices, and the larger streams or rivers, to be marked on this diagram, to be returned as soon as possible to the Post Office Department."