This wasn't exactly on a trail, but I have to mention it. My son and I were walking in a March Of Dimes walk, when we came across a full deer skeleton on the side of the road. I collect skulls, so I took the skull and put it in one of the doggie pick up bags I had brought to pick up after my dogs. The walk was 10 miles and this was early on in the walk. The whole way my son kept saying that we had to go back for the rest of the skeleton to reassemble it for 4-H. When the walk ended we got our car and drove to the skeleton to collect the rest of it. We put the pile of bones in the back of my small station wagon. When I went to put the skull in, I realized that I had lost a bone from the lower mandable through a hole in the bag. I drove the entire route to look for the lost bone. Part of the route took us up the driveway of a funeral home. By the time I drove to this point, a wake was going on, and they usually come out to assist you with parking, since the lot is small. When the man approached my car, I said that I was just driving through, which is wierd in itself, because why would you drive up a funeral home driveway for no reason. My son blurts out, "Oh, look what we have in the trunk!" The man turns to see the pile of bones in my trunk. It was quite a big pile. I high- tailed it out of there, hoping the police wouldn't soon follow. I never did find the lower mandible, but the rest of the deer we still have, on a shelf in my garage. We never did quite get it back together.

This is one of the funniest scenarios I've ever read! People in the library are staring as I am laughing out loud.
Yeah I also collect skulls, though usually ONLY find the lower jaw!

I found an old farmer's ditch that was filled with junk, including a couple of complete cow skeletons and pieces of various farm equipment. The cow skulls are enormous. The spot was so unusual I put a letterbox there and called it "The Farmer's Treasure."