I found nothing on "P. Rawling" but did find info that the "Little Art Shop, Inc." was a mail order business in Washington DC in the teens and 20's. They advertised nationwide in magazines for folks to "Earn money fast" selling postcards.
My first thought about your picture was C & O canal tow path, but it's too far from the water's edge I think. And by 1926, the canal restoration was well underway and those trees between the path and the water would have been removed. So... it could be any where.
DCMatt