Long Pond Trail follows the 15-Mile Creek stream valley, winding over ridges and valleys with several steep ascents and descents that make it one of the most challenging trails at Green Ridge State Forest. It is named for the remote area where 15-Mile Creek pools into a long rectangular pond-like area. The hike descends through the Potomac Bends Wildlands to the Potomac River, whose confluence with 15-Mile Creek was a pioneer landmark; from there it was 15 miles to Oldtown, which gave the creek its name. The trail also descends and connects to the towpath on the C&O Canal National Historic Park, and the Potomac River borders Green Ridge State Forest for approximately 30 miles.