Thanks surf!
The rocks that i'm finding are very big and look very old. The property has more rock dumps than bottles, metal, etc. combined. I would say that the property has about three individual rock dumps. I have found pieces of brick and old cow bones underneath but no glass bottles or anything big. The dump with the big rocks i located on a bank alongside a stream. My best find so far is a 1880s stove door with a round ornament in the door in perfect shape.
Looking at the picture above, the dump shown has some tin cans like the one at the dump but no really old bottles yet. could the old bottles be underneath the huge rocks?
Currently there is snow on the huge rocks and the dump site itself but will see what I can do about pics once the snow melts.