It is the centerpiece of the Crab Orchard National Wildlife Refuge .
Crab Orchard Lake is a 6,965 - acre ( 28.2 km2 ) reservoir in Williamson County , Illinois .
Crab Orchard Lake is the centerpiece of the Crab Orchard National Wildlife Refuge .
Crab Orchard Lake is a 6,965 - acre ( 28.2 km2 ) reservoir in Williamson County , Illinois .