In the back property we have a creek that cuts all the way across from property border to border. So to reach the back 5+ acres, I built a bridge out of available materials. I found a good crossing point, cut down some oak trees, dragged them across and used a reclaimed deck for decking the bridge. I'm now on rebuild #4 of the bridge. The bridge works great for people, lawn tractor, and go-karts. I cut a ford for the tractor to use when it's dry.
Sorry no pics of the completed bridge or for builds #2 and #3 - I had picture of the tree down and the bridge twisted but can't find it now! Here is the most recent update - now have two strong trees (bigger then the originals) down. I have to replace a few planks that have rottend, do a little ground work on the ends, and screw down the planks, but here is the new bridge for 2013. Oh, and Braxten is now driving the tractor (at 9).