What are words that describes the land in Iowa?

The vast majority of Iowa’s terrain consists of gently rolling to nearly level, fertile prairies of windblown glacial soil called ‘loess’. In north-central and extreme northern Iowa occur the Iowan Erosion Surface and Des Moines Lobe areas, where more rugged terrain remains as the result of active windblown and water erosion during prehistoric periods. Iowa also contain areas that are heavily eroded river bluffs in eastern and south-central areas and steep hills in the northeast known as the Driftless Area, which escaped glaciation, and contains deep and broad river valleys of the Mississippi, Wisconsin, Turkey, Wapsipinicon, Maquoketa, Upper Iowa, Oneota, Cedar, Skunk, Des Moines, Big Sioux, Boyer, Little Sioux, Floyd, and Rock Rivers.