This project will construct wildlife crossings and directional fencing in the Mojave Desert at three locations along I-15 near Cave Mountain (PM R116.70), Soda Mountain (PM R129.75), and Clark Mountain (PM 168.05). The bridges are proposed to be three-span cast-in-place/prestressed concrete box girder structures with openings for the existing NB and SB I-15 lanes and the future BLW rail in the median. The bridges are proposed to be 100 feet wide, 240 feet to 400 feet long, and the spans will accommodate space for one additional future travel lane in each direction. Railing and fencing will be installed at the edges of the bridges and chain link directional fencing will also be installed at various lengths along the access control line to direct wildlife to the crossings. The limits of this fencing will be based on recommendations from wildlife experts. The surface of the bridges will be composed of native materials to match the characteristics of the surrounding areas. Other bridge types may be considered during the design phase.