There are dozens of local race events.  To list all the 5K, 10K, half marathon or marathon relay events would fill a few pages.  Search for events when you click these links:

Running In The USA
http://www.runningintheusa.com/Classic/List.aspx?State=MD

Charm City Run
http://www.charmcityrun.com/race/

Blue Cheetah Sports Timing
http://www.bluecheetahtiming.com/race-calendar

FIND A 5K, 10K, HALF MARATHON RELAY OR MARATHON RELAY EVENT