US 160 is a principal rural arterial roadway that traverses the southern portion of Colorado from border to border. In La Plata County, US 160 crosses the scenic San Juan Mountains over mountain passes and through picturesque valleys. At a location about five miles west of the town of Bayfield, there are a large number of wildlife accidents as the highway crosses migration routes for deer and elk. Also, between Durango and Bayfield the existing two-lane road winds through the mountain environment with few opportunities for passing slow moving vehicles and trucks. The goal of the US 160 Passing Lanes Project at Dry Creek is improving safety along a 1.35-mile length of US 160, by constructing wildlife crossings to minimize vehicle and wildlife conflicts, and providing opportunities for passing by widening US 160.Muller prepared the design for four bridges, dval pre-cast arch structures and a double 20-foot span box culvert. Two of the bridges carry US 160 westbound and eastbound over Dry Creek and were designed with BT42 prestressed girders. These bridges also serve as a passage for wildlife. To the east of Dry Creek, two of the bridges carry US 160 westbound and eastbound over the East Wildlife Crossing. These bridges were also designed with BT42 prestressed girders. The double box culvert carries CR 223 over Dry Creek. The dval pre-cast arch structures span a second wildlife crossing. Phase 1 of the project is complete and includes the dval pre-cast arch structures and associated roadway widening. Phase 2 design is complete with construction timing relying on future funding.