Delta National Forest in western Mississippi's Sharkey County covers 60,898 acres and stands out in the National Forest System as both one of only six forests contained within a single county and the system's only bottomland hardwood forest. Administered from Jackson, with the Delta Ranger District office in Rolling Fork, it is operated as the Sunflower Wildlife Management Area through an agreement between the U.S. Forest Service and the Mississippi Department of Wildlife, Fisheries and Parks. Its Green Ash-Overcup Oak-Sweetgum Research Natural Areas preserve a rare pristine bottomland hardwood forest and were designated National Natural Landmarks in May 1976, highlighting the forest's ecological importance in the lower Mississippi Delta.