State Route 73 is part of Maine

Maine

Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...

's system of numbered state highways. It runs 10.74 miles (17.3 km) from an intersection with State Route 131 in St. George

St. George, Maine

St. George is a town in Knox County, Maine, United States. As of the 2000 census, the town population was 2,580. It includes the villages of Port Clyde, Clark Island, Glenmere, Martinsville and Tenants Harbor, the latter its commercial center. A favorite with artists, writers and naturalists, St...

 to an intersection with U.S. 1

U.S. Route 1

U.S. Route 1 is a major north–south U.S. Highway that serves the East Coast of the United States. It runs 2,377 miles from Fort Kent, Maine at the Canadian border south to Key West, Florida. U.S. 1 generally parallels Interstate 95, though it is significantly farther west between...

 in Rockland

Rockland, Maine

Rockland is a city in Knox County, Maine, in the United States. As of the 2010 census, the city population was 7,297. It is the county seat of Knox County. The city is a popular tourist destination...

. The route is also known as Seal Harbor Road (in St. George), Spruce Head Road (in Spruce Head), Elm Street (in South Thomaston

South Thomaston, Maine

South Thomaston is a town in Knox County, Maine, United States. The population was 1,416 at the 2000 census. A fishing and resort area, the town includes the village of Spruce Head.-History:...

), and Weskeag Road, Ingraham Drive and South Main Street (in Rockland).