"U.S.--IL--Lusk Creek Area." . . "U.S.--IL--Pope Co." . . "Lusk Creek Region (Ill.)" . . . . "U.S.--IL--Shawnee National Forest." . . . . . . . "Maps" . . . . . . . . . "Geochemical survey of the Lusk Creek Roadless Area, Pope County, Illinois" .