The narrow band of the southern area of Iowa, which runs parallel to the state of Missouri, exhibits a much flatter terrain than one finds to the north. The four eastern counties—Jefferson, Van Buren, Wapello, and Davis—present a landscape, town patterns, and architecture closely related to those found along the Mississippi River. The Des Moines River, which traverses the eastern part of this section of Iowa, was navigable by smaller steamboats, at least during the spring of each year, but the rest of the region had to await the advent of the railroads and highways for its principal transportation linkage.

Within the cities of Keosauqua and Ottumwa on the lower Des Moines River there are a number of excellent examples of pre-1860s buildings; and in the small, bypassed community of Bentonsport one is easily carried back into the 1850s. To the west, Osceola and Red Oak convey the flavor of the late nineteenth-century Victorian period or that of the early decades of this century. Other attractions of this region are the landscape and architectural designs of the numerous state parks, several of which were developed adjacent to dams and their extensive reservoirs.