The only church I can find in Hagerstown is an Evangelical Free

Tri-State Fellowship, an EFC
(301) 790-1774
13153 Cearfoss Pike
Hagerstown, MD 21740-1611
tsf@tristatefellowship.org
http://www.tristatefellowship.org/index.htm

There are two PCA churches in Washington county

Grace Christian Fellowship Hancock MD 301-678-6036 gcfpca@juno.com
131 Pennsylvania Avenue
21750-1135

Grace Reformed Fellowship 15251 Falling Waters Rd Williamsport MD 301-797-6784 Potomac Rev. Garry L. Knaebel

In Frederick County I found an OPC church in Frederick

NEW HOPE - Frederick, MD
Address
211 W. Patrick St.
Frederick, MD 21701-5515
Meeting At
Parkway Elementary School, 300 Carroll Pkwy.
Services: 9:30 a.m.
Sunday School: 11:10 a.m.
Pastor: Richard N. Ellis
Email: ellis.1@opc.org
Phone: 301-694-3595
Website: http://www.newhopeopc.org

And an ARP church

Reverend Peter J. Kemeny, Pastor pastor@goodnewspres.org
Good News Presbyterian Church http://www.goodnewspres.org/
PO Box 1051
Frederick MD 21702-0051
301-473-7070

I also found a couple of Reformed baptist churches in Walkersville. Let me know if you want details of these. I didn't extend the search into WV or PA since they seem less populated than the Hagerstown area. Let me know if you would like me to do so.

Let us know how you get on.

Yours in Christ,

James.