At the eastern edge of the bay it enters the city of Muroran where it ends at an intersection with National Route 36.

National Route 37 is an 81.1-kilometer-long (50.4 mi) highway in southwestern Hokkaido that runs east from Oshamambe to Muroran.

Its eastern terminus lies at an intersection in central Oshamambe where it meets national routes 5 and 230.

From there national routes 37 and 230 travel together paralleling the coastline of Uchiura Bay and the Dō-Ō Expressway.

[2] On 4 December 1952 the route was designated as Primary National Highway 37 between Oshamambe and Muroran.