Some unique features of the Mark Twain include Greer Spring. It is the largest spring on National Forest land. It is part of the Eleven Point National Scenic River. The spring pumps an average of 214 million gallons of water per day into the river. The public can also visit the Glade Top Trail National Scenic Byway, which offers views of over to the Boston Mountains in Arkansas. Part of the Ozark Trail system winds through the National Forest.