Probably the person locally who knows the most about the old church buildings is Susan Young of the Shiloh Museum in Springdale (479-750-8165). She mounted an exhibit on the subject a couple of years ago and traveled the whol region studying them. She's very nice and approachable. On the grounds of the Shiloh Museum there are a number of old buildings, all beautifully restored, and the grounds themselves are beautiful. The same is true of Battlefield Park in Prairie Grove and Pea Ridge Park in Pea Ridge (not in Washington County, but not far). If you wanted to photograph a number of buildings in a short time, a trip to these three places would be a great way to do it.