Named after the two islands that exist in the park- Diamond Island and Hurricane Island- the fish and wildlife area stretches between the Godar Swamp and Illinois River. The natural preserve is located just north of Hardin in Calhoun County and the Calhoun County Fairgrounds. Boating, fishing, and hunting is offered and river access can be found on the west side of Diamond Island at the Godar Diamond River Access Area which also has pull-offs and parking lots perfect for stargazing. The land and rivers are rich in native fish and wildlife species like American bald eagles, white-tailed deer, songbirds, as well as various reptiles and amphibians.