Be ready for lots of boards. Lots. Boards with 90-degree turns in them while over swampy, nasty water. Then skinnier, straight boards over equally swampy, nasty water. Falling off in any of these situations will cause at least a wet foot, and at most, a complete over-the-bars face plant into the swamp water. Walk the boards first if your balance skills aren't up to par.
This is the best trail to use to get from the Butler Trail
to the Lower McKinley Trail
by the edge of route 680.