United States. Soil Conservation ServiceBase compiled in 1976 from USGS 1:24 000 and 1:62 500-scale topographic maps dated 1922-1971, revised from aerial photographs taken 1974 and 1977; interpretations derived from soil map constructed 1974.; "Projection and 10 000-meter grid ticks, zone 16: Universal Transverse Mercator."; "25 000-foot grid ticks based on Illinois coordinate system, west zone."; May 1979.; Includes location map.53 x 81 centimetersJPEGUMN_ALMA:9931709540001701engDept. of Agriculture, Soil Conservation Service (Washington.)PublicAgricultureRock Island Co., IllMapsIllinois--Rock Island CountyIllinoisUniversity of Minnesota