Just found a milk bottle dated 1911.

I've got many dozens of old bottles, 95% of which have been found at

1. Former bottle dumps.
Look just past old fence lines of properties. Back in the old days when all trash was burned, folks would dump their bottles over the fence "out back".
If you're ever out in the boonies or in the woods, and find an old fence line, walk it and look close.

2. near Cemeteries. If you know of old cemeteries on the edge of a woods, look in the woods: I've found dozens and dozens of old bottles that I assume must have been tossed there by the grave diggers.

... just thought I'd pass it along.

You should have course ensure that you are not trespassing on private property!