Not completely backcountry but every year we cut our firewood from the same stand of old growth forest on the CO front range. Couple years back I went to throw another log on the fire and there was a horseshoe glowing red in the fireplace. This had to be inside a piece of pine that somehow I never hit with the chainsaw or splitter. Still nails in the shoe even. I am guessing someone hung it on a small branch some 100 years ago and the tree had to have grown completely around it.