The last segment of US 8 in Wisconsin was paved in 1937 between Cavour and Armstrong Creek; the highway in Minnesota was paved in its entirety by 1940. Near Hawkins, a pair of sharp curves near the Rusk–Price county line were removed as the State Highway Commission realigned the highway to follow a straighter course. The US 8/US 51 concurrency was altered the next year to a shorter overlap running southward near Heafford Junction. The former routing of US 8 was redesignated County Trunk Highway K (CTH-K) after it was transferred back to county control.