Within the park there is decent network of trails to ride. Nothing technically really. It's a fun ride in the woods. The best section of the trail is outside the park actually. The south side of the trail ends on Democracy Blvd near it's intersection with Seven Locks road. Make a left on Seven Locks rd and pedal (~.25 mi) until you see a sign (clearly marked, can't miss it) for the Cabin John trail. The section between Seven Locks and Bradley Blvd is sweet, sweet singletrack with some nice decents/climbs depending on dircection, but only 1.5 miles. The next section between Bradley Blvd and River Rd is just okay. It's flats but really, really rooted everywhere. The next section between Bradley Blvd and Seven Locks lower down is nothing special. The next section along Seven Locks is fun and a bit more tech with sharp cornering and 2 tight stream crossings. After that section the trail becomes a hike a bike unless your super man.