The project to be evaluated in this feasibility study is the construction of two wildlife overpasses at two locations within the Dome Mountain priority site at approximately RP 19.3–19.5 and RP 17.6–18.5 on US-89. This engineering feasibility study will determine the exact overpass locations as well as the size, dimensions, and details of these structures. These crossing structures will require exclusionary fencing to keep wildlife off the highway, reduce wildlife vehicle collisions (WVCs), and guide wildlife towards the safe crossing opportunities provided by the structures. Fencing associated with these overpasses will need to be an approximate height of 8 ft, and extend between approximately RP 16.5–22, with the exact locations determined through the feasibility study. Fences will need wildlife jump-outs. Fencing associated with each structure should span approximately 1.5 miles in either direction of the structure, with cattle guards, electric mats or other treatments installed at any property access sites within the fenced section to keep wildlife from entering the fenced corridor. This project also includes the reconfiguring of the existing riprap under the Point of Rocks bridge over the Yellowstone River (approximately RP 20.4) at the bridge ends to promote safe passage of wildlife under the existing bridge. Fencing, jump-outs, cattle guards, and potentially electric mats will also be a part of this work, just as with the overpasses.
