I've seen these contraptions on telephone poles before to keep squirrels from climbing them, but why is there one here? I'm sure it had it's use when the railroad used to go through here. A little bushwhacking will be required to reach the cache, but should be an easy find unless a squirrel finds it and takes it home with him.
Update: This cache is NOT winter friendly. It would also be impossible for a squirrel to open, move, or take the cache with him or her.