We did this hike last week and it was a lot of fun. Parking at the visitor center and starting the trail from there is a must. It starts out with .6 miles up hill which takes you to a split. You can either goto the Washington monument or Annapolis rocks. I would suggest goto the monument, then to Annapolis rocks. The 12 mile hike is well worth your time! There will be a lot of rock, so wear supportive shoes.
Beautiful setting but the state of MD is letting this jewel go rusty. For biking the trail has deteriorated over the past few years. Very bumpy, and the latest insult is the fact that they dug it up for gas lines and did not restore the trail to a decent shape. I hope some maintenance can be done on the trail