I am in Baltimore, MD; does anyone know of any 2013 Gravel Grinder or Ultracross races/ events in the Mid-Atlantic (PA-MD-VA)?
I am only aware of the Iron Cross held in October at the Pine Grove Furnace State Park, PA: http://ironcrossrace.blogspot.com/
I am also looking for recommendations for similar type training routes in the 50K - 100K length within an 90 minute drive from Baltimore.
I don't know of any specifically beyond what you mention, though the first site below has some info for routes in/around Loudoun County, VA so not too far from you. The second has a good national calendar and info. The Ultra site appears to be down, but has the listing for their races. Hopefully there will be some more.....