Iowa DNR
River & Stream Biological Monitoring
Fish and Benthic Macroinvertebrate Surveys
Physical Habitat Assessments

Ecoregion 47b : Des Moines Lobe

Ecoregion Map
Ecoregion Characteristics
Landform Description
Smooth to irregular plains. Elevation 900-1500 ft.
Surficial Materials
Loamy till with no loess.
Mollisols (Hapludolls) {Clarion-Nicollet-Webster}
Annual precipitation 28-31 in. Freeze free: 145-160 days.
Potential Vegetation
Bluestem prairie
Predominant Land Use
One of the youngest and flattest regions in Iowa, the Des Moines Lobe ecoregion is a distinctive area of Wisconsinan glacial stage landforms currently under extensive agriculture. In general, the land is level to gently rolling with some areas of the moraines having the most relief. The morainal ridges and hummocky knob and kettle topography contrast with the flat plains of ground moraines, former glacial lakes, and outwash deposits. A distinguishing characteristic from other parts of Ecoregion 47 is the lack of loess over the glacial drift. The stream network is poorly developed and widely spaced. The major rivers have carved valleys that are relatively deep and steep-sided. Almost all of the natural lakes of Iowa are found in the northern part of this region. Most of the region has been converted from wet prairie to agricultural use with substantial surface water drainage. Only a small fraction of the wetlands remain, and many natural lakes have been drained as a result of agricultural drainage projects.