You may assume that Maryland Distilleries would be mainly around Baltimore, but that's not entirely the case. There is only one Maryland Distilleries that is located directly in Baltimore, the rest are scattered across the state and will take you a long time to tour them all but it is definitely worth doing so!
The Free State has around 20+ Distilleries as of now plus the Maryland Distiller's Guild. So, even though they are not very convenient to tour each one easily, it is still worth the trips out to them. Just a little known fact around here, our CEO here at Grape + Whiskey is from Maryland, so maybe that's why he loves this place so much too! Whether you live locally or are visiting, it is worth it to check them all out and be sure to frequently come back to this site as more and more of them are getting added each day. Tours typically last from 30 to 60 minutes per tour and they are well worth your time to check out the different ones. Each one has their own flavors and charm to experience.
What is even more awesome is that most distilleries offer free samples of their liquor when you go through a tour as well. The tours are extremely interesting and fun to do too. They aren't just there to sample the liquor that you're looking forward to but are actually very informative and you get to meet a lot of like-minded people usually that are also doing the tour. - Be sure to call ahead if you are planning on doing a tour at one of the distilleries to check on availability.