Mountain biking in Balt/D.C. area

So a buddy and I are heading out to most likely patapsco state park tomorrow to do some mountain biking.

Has anyone been on these trails and knows where to park or any other suggestions as to where to go?

Check out the trail reviews on MTB Review. http://trails.mtbr.com/cat/united-states-trails/trails-maryland/trail/PRD_168264_4553crx.aspx They include directions and suggestions.