Subwatersheds - 14-digit Hydrologic Units, 1991 (1:24,000) Shows the boundaries of subwatersheds in Indiana. Actual hydrologic units often extend beyond the state and county boundaries. The U.S. Geological Survey maintains a set of 1:24,000-scale paper topographic maps with hand-drawn drainage divides for streams with drainage areas greater than 5 square miles. The U.S. Geological Survey digitized these drainage divides. The NRCS assigned each delineated drainage basin a 14-digit hydrologic-unit code (HUC).

IndianaMap, IGS, Indiana, HUC, Hydrologic Unit Code, Hydrologic Unit Boundary, Watershed, Hydrology, subwatershed, inlandWaters

U.S. Geological Survey