Greenbrier State Park features 5 miles of hiking trails near Frederick-hagerstown, MD.
From the East: Take I-70 west to exit 42. Bear right onto Rt. 17 north (follow signs). Go into the center of Myersville and Rt. 17 will turn right. Follow Rt. 17 to the flashing lights at the intersection of Rt. 40. Turn left onto Rt. 40 west. Follow for three miles and the park is on the left. From the West: Take I-70 east to exit 35. Bear right onto Rt. 66 (follow signs). Go straight to the stoplight at the intersection of Rt. 40. Turn left onto Rt. 40 east. Follow for two miles and the park is on the right.
http://www.tripleblaze.com/trail.php?c=3&i=386