U.S. Route 101
The nearly highway's northern terminus is in Tumwater, Washington: the route remains along the Olympic Peninsula's coastal perimeter west, north, and east; the northernmost point on the highway is in Port Angeles. The southern terminus of US 101 is in Los Angeles at the East Los Angeles Interchange, the world's busiest freeway interchange.
Illinois Route 101
Route 101 begins at a junction with Route 61 in Augusta, in Hancock County. The route leaves Augusta to the east and crosses into Schuyler County, entering Weinberg-King State Park across the county line. The highway continues east past the park until the community of Brooklyn, where it meets Route 99. After passing through Brooklyn, Route 101 heads eastward through Littleton before terminating at a junction with U.S. Route 67.