Iowa's bedrock geology generally increases in age from west to east. In northwest Iowa Cretaceous bedrock is ca. 74 million years old; in eastern Iowa Cambrian bedrock … See more

As in most of the U.S., surface water in Iowa is never safe to drink untreated, contamination by agricultural runoff including nitrates, herbicides, pesticides, and animal waste is common, though the Clean Water Act has helped. Municipal water supplies are … See more

Devonian Fossil Gorge
Floods in 1993 washed away all the soil and unconsolidated bedrock along the spillway of the See more

Despite popular perception, Iowa is generally not flat; most of the state consists of rolling hills. Prior divides Iowa into eight See more

Iowa has a humid continental climate throughout the state (Köppen climate classification Dfa) with extremes of both heat and cold. The average annual temperature at Des … See more

The NRCS divides Iowa into 23 soil regions. In general, soils of southern, eastern, and western Iowa are loess-derived, while soils of northern and central Iowa are till-derived. Most level areas of Iowa have soils highly suitable for agriculture, making … See more

Samuel Calvin (1840–1911) was Iowa's first systematic geologist, who helped to make the first bedrock and landform maps of Iowa, as well as lead geological research throughout the state. Calvin Hall at the University of Iowa is named for him. Clair Cameron … See more