This detailed and colorful geological map is from Owen's report, submitted in 1851 and published in 1852. Assisted by J. G. Norwood, C. Whittlesey and other noted scientists, Owen's report made major contributions in several fields. The map itself shows an abundance of geological types via hand coloring. It also shows the Iowa coal-field extending into northern Missouri and part of the Illinois coal-field. There is excellent detail of watersheds and lakes throughout. Features an inset "Geological Map of the North Shore of Lake Superior" which is drawn on the scale of the original manuscript map.

References: Rumsey #0690.

Condition: B

Issued folding with light toning, scattered foxing, and dampstains at right.