What part of Maryland are you in? There are a TON of DOs at University of Maryland/Baltimore-Shock Trauma. I mean a ton. A lot probably has to do with observational selection bias on my behalf, but I've seen them in the trauma bay, CCU, CCRU, and MSTICU.
On the west end of the state, I've come across a couple in the ERs at Frederick Memorial and Western Maryland Medical Center as well. If you're closer to Allentown, PA then try there (President of ACEP is a DO and Sr Vice Chair of EM there).
Inova Fairfax has a bunch, mostly residents though. One ER attending, two surgical residents, and one peds resident off the top of my head. They're out there...you're best bet is to use one of your connections to put you in touch with one.