depends on the stream and site. easiest way is to drop a couple good sized logs (8"-10" or so) and pre-cut some 2x6 lumber and them make the bridge on-site. if you can get there with a atv, you can get the materials and tools in. this, however, is best on short spans (say <20' or so). we have one at our place and have a couple in the Adirondacks. one other thing to be mindfull of is high water. if it floods, your bridge will be downstream somewhere. we have one of ours anchored in the gound and to some trees.