Iowa Department of TransportationThis coverage outlines the boundary of the Loess Hills in Iowa at 1:100,000 scale. Criteria applied to the delineation of the Loess Hills included drainage density, drainage divides, density of isolated hillforms, crenulated contours, slopes greater than 15%, presence of catstep features, general loess thickness and earlier mapping. The following sources were utilized: 1:100,000 and 1:24,000 scale USGS topographic maps, USDA-NRCS STATSGO Soil Survey Grid Information, Digital Elevation Module, and the 1:2,000,000 Landforms of Iowa Coverage.ArcGIS FeatureLayerhttps://hub.arcgis.com/datasets/09e217a399134a428b883f96d39debf9_0engIowaDOT Open DataPublicLoess Hills [Iowa]Web servicesIowaLast Modified: 2020-06-18