Maybe it's not common knowledge because I don't think I knew this until a few years ago, but deer "stash" their fawns in what they deem safe places for lengths of time while they go off and do deer things. Fawns are spotted for camouflage and are very still and will usually stay where they've been stashed. If you find a fawn alone, the best course of action is to do nothing because mama will come back. Of course if it's been days or if the fawn appears injured or sick, then probably best to call a wildlife place and let the professionals deal with it.