An old powder house?
A tree makes for a good road signpost.
The famous Gin Mill, established in the late 1880's. (Notice the tree growing through the porch.) *This may not be the original 1880's building, I must dig up my notes to be sure. This might be a 1920's era structure.
A gust of wind sprung up and blew forest-fire smoke away for a few minutes, while I took the powder-house photo. It soon settled back in to pollute the next photographs.