Where I grew up, it wasn't uncommon to find toppled fences, old power lines, whatever. It's heavy snow country so putting up fences are usually out of the question, yet every summer, some moron (usually from the valley) insists on putting up a fence of some kind. The locals just put up No Trespassing signs or they build rock walls or use heavy timber.
Unfortunately, one common moronic method of fencing was tapping trees as fence posts and stringing barbed wire. Usually, the seasoned natives would cut the barbed wired down for safety reasons. One summer, a couple of out of town high school kids were riding dirtbikes when one of them came across a section of barbed wire mounted between trees. He was riding so fast, the barbed wired cut his neck all the way to the spine then wrapped around him. The other kid(s) had no clue what happened and kept riding.
It was about four days of searching and retracing the trail before S&R found him.