a mile where it exits with U.S. 6 and heads northeast through Commerce City. In just a few miles the US 6/US 85 concurrency merges with I-76 at mile marker 9. They travel concurrently for until exit 12 when US 85 becomes an expressway and continues north out of the Denver area through Brighton. From there it parallels I-25 for about passing through Fort Lupton, Platteville, LaSalle, Evans, Greeley, Eaton, Ault, Pierce, and Nunn before crossing into Wyoming. Wyoming US 85 enters Wyoming from Colorado south of Cheyenne. In Cheyenne it joins with Business Route 87, and a mile later with I-180 until it meets with US 30. The segment with I-180 is the only fully at-grade interstate route in the U.S. At exit 12, it joins with I-25 and US 87 in a concurrency for until US 85 leaves at exit 17 and travels northeast towards Meriden. From there it heads north to Torrington, where it meets with US 26 and concurrencies for until Lingle, and later it meets US 20 and US 18 at Lusk. It shares the next with US 18 and later meets US 16 near Newcastle. From here it is until it enters South Dakota in the Black Hills. South Dakota The South Dakota section of US 85, with the exception of two concurrencies with US 14 Alternate and a concurrency with I-90, is defined at South Dakota Codified Laws § 31-4-181. US 85 enters the Black Hills from Wyoming and travels northeast until it meets with US 14 Alternate east at Cheyenne Crossing. The two routes form a concurrency from there, along the way coming to the road which leads to Terry Peak. Upon entering to Lead, the two routes are separated, and the overlap with US 85 is replaced by a truck route. As the route US 85 and US 14 are separated until both meet again in Deadwood, but not before US 85 serves as the northern terminus of U.S. Route 385. The routes run together through Deadwood before splitting, and US 85 then runs north to meet I-90. US 85 overlaps I-90 for while heading west. At exit 10 on the north side of Spearfish, US 85 heads back north. At Belle Fourche it crosses state highway 34 and US 212. From there it continues to North Dakota passing only through the small towns of Redig, Buffalo (where it meets state