If you are looking to put a bridge on State Park land I would check with the local Boy Scouts, they make a lot of the bridges for the SPs. I know this because some friends and I spent our hard earned money to built a well thought out safe, wide and secure bridge in a local SP only to have it ripped out a year later for a new bridge built by the local Boy Scouts. I appreciate the work that they do but if i was going to do it again, i'd check with them so we didn't waste our time and money on a bridge that they had all ready planned to build. We could have used our lumber to fix a different area.