Some adventurers were paddling along the river when they stumbled upon what they thought might be a dead body. As they got closer, they realized that it was a prosthetic leg that had been repurposed as construction material for some clever beavers. They pulled out the leg and, believe it or not, found the original owner on the internet.

The owner of the leg had lost it on a canoeing trip earlier in in the summer. Apparently it wasn't a big deal since it wasn't his "everyday leg". You can't make this stuff up.