Nearly all of the bridges you see on the refuge are water control structures. In some pools higher water levels are maintained throughout the year to provide protection for nesting waterfowl and common loons, stunt vegetation growth, and secure fish populations during the winter. In other pools water levels are manipulated on a seasonal basis. In late summer the water levels may be lowered to create mudflats for cranes, shorebirds, and other species. Although this bridge is newer, many of the original bridges built by the Civilian Conservation Corps (CCC) can still be found on the refuge. The CCC operated at Seney from 1936 to 1942 as a work relief program for unemployed, unmarried men between the ages of 17-28. It provided food, clothing, shelter, and a wage of about $30 per month. Seney National Wildlife Refuge would not have been possible if it was not for the hard work of the CCC.