Copied & pasted from their website:

The park, comprised of 6,300 acres, extends along 14 scenic miles of Seneca Creek, as it winds its way to the Potomac River.

The park features hiking and biking trails, boat rental, fishing, flatwater canoeing and kayaking, historic interest, hunting, picnicking, playgrounds, riding trails, picnic pavilions, a restored 19th century cabin, cross-country skiing and vending refreshments.