St. Louis. The route ends just east of South Broadway, at the Interstate 55 overpass. Due to the nearby east terminus of I-44, there is no interchange with I-55 at the state route's terminus. The Lewis and Clark Trail Most of Route 100 is part of the Lewis and Clark Trail. From Kirkwood Rd in Kirkwood to three miles (5 km) west of Wildwood is one section, where the trail turns off on Route T. Route T will eventually end, once again, at Route 100 northwest of I-44 and continue down Route 100 all the way to five miles (8 km) north of Linn (where Route 100 ends), and the Lewis and Clark Trail turns off onto Route C. History Much of the road between St. Louis and Gray Summit was the original U.S. Route 66, though this was only temporary until US 66 moved to its later location at what is now Watson Rd (Route 366) and Interstate 44. During, and after US 66 was moved off Manchester Rd, the road remained part of U.S. Route 50 for many years. Major intersections References 100 100 Streets in St. Louis U.S. Route 50 Transportation in Osage County, Missouri Transportation in Gasconade County, Missouri Transportation in Franklin County, Missouri Transportation in St. Louis County, Missouri