Geological survey of Wisconsin, Iowa, and Minnesota, by D.D. Owen.
Geological report of a survey of portions of Wisconsin and Minnesota, made during the years 1847, '48, '49 and '50 ... by J.G. Norwood.
Geological report of that portion of Wisconsin bordering on the south shore of Lake Superior, surveyed in the year 1849 ... by Charles Whittlesey.
Geological report of local, detailed observations, in the valleys of the Minnesota, Mississippi, and Wisconsin rivers, made in the years 1848 and 1849 ... by B.F. Shumard.
Description of the remains of extinct Mammalia and Chelonia, from Nebraska Territory ... by Joseph Leidy.