Soil Survey Geographic Data Base (SSURGO) are the soils across McLeod County. Soils, Aerial Photos, and Sections are combined to illustrate the areas of soils within and relative to section lines and terrain features. The value of each polygon appears at its centroid. Each boundary does have a value and larger areas may require some attention to locate the value. Each township has been quartered and processed into pdf files which are available at the bottom for viewing. Each is approximately 3 MB.
The following information has been copied from the NRCS Metadata and explains how the SSURGO boundaries were established.
Originator - U.S. Department of Agriculture, Natural Resources Conservation Service
Abstract - This data set is a digital soil survey and generally is the most detailed level of soil geographic data developed by the National Cooperative Soil Survey. The information was prepared by digitizing maps, by compiling information onto a planimetric correct base and digitizing, or by revising digitized maps using remotely sensed and other information.
This data set consists of georeferenced digital map data and computerized attribute data. The map data are in a soil survey area extent format and include a detailed, field verified inventory of soils and nonsoil areas that normally occur in a repeatable pattern on the landscape and that can be cartographically shown at the scale mapped. A special soil features layer (point and line features) is optional. This layer displays the location of features too small to delineate at the mapping scale, but they are large enough and contrasting enough to significantly influence use and management. The soil map units are linked to attributes in the National Soil Information System relational database, which gives the proportionate extent of the component soils and their properties.
1 SSURGO KEY Prime Farmland Map