Mountain forests, streams, and valleys make up 12,000 acres in Potomac State Forest. The Potomac State Forest drains into the Potomac River Basin. Potomac State Forest features the highest point in any Maryland State Forest-Backbone Mountain, elevation 3,220 feet. Another high point in the forest is the rock outcropping near the intersection of Maryland Route 135 and Walnut Bottom Road which overlooks a portion of Potomac State Forest, Savage River State Forest and Crabtree Creek.