From DC, take the Baltimore/Washington Parkway (Route 295) North, to Exit 22 for Powder Mill Road-Beltsville. Turn right (east) onto Powder Mill Rd. and go approximately 2 miles until you reach the traffic light at the intersection of Route197 and Powder Mill Rd.  The main gate of PWRC is straight ahead. 
 

From Baltimore, take the B/W Parkway (Rt. 295) South to the Laurel/Route 197 exit.  Turn left onto Rt. 197.  Follow 197 approximately 1 1/2 miles to the PWRC main gate on the left (opposite the intersection with Powder Mill Rd.).