Interesting. Wonder how it got there? Maybe an old homestead near by. From the looks of the woods and the estimated age of the frame. I would strongly suggest exploring in greater depth
You can tell by the right crank arm that it is old. Arm is straight meaning the bike had no chainguard. Chainguards came in the 20's and the crank arm was curved after that to allow clearance. I'd guess a 20's bike. Gary