US Highway 12

U.S. Route 12
Route information
Length:	2,484 mi (3,998 km)
Existed:	1926 – present
Major junctions
West end:	US 101 at Aberdeen, WA
	I‑5 near Chehalis, WA I‑15 at Helena, MT I‑94 at Forsyth, MT I‑29 at Summit, SD I-35W at Minneapolis, MN I-35E at Saint Paul, MN I‑39 / I‑90 at Madison, WI I‑94 at Chicago, IL I‑65 / I‑90 at Gary, IN I‑94 at New Buffalo, MI
East end:	Cass Avenue in Downtown Detroit, MI
Location
States:	Washington, Idaho, Montana, North Dakota, South Dakota, Minnesota, Wisconsin, Illinois, Indiana, Michigan
Highway system
United States Numbered Highway System List Special Divided Replaced

U.S. Route 12 (US 12) is an east–west United States highway, running from Aberdeen, Washington to Detroit, Michigan, for almost 2,500 miles (4,000 km). As a thoroughfare, it has mostly been supplanted by I-90 and I-94, but remains an important road for local and regional travel.

The highway's western terminus is in Aberdeen, Washington at an intersection with US 101, while the highway's eastern terminus is in Downtown Detroit, at the corner of Michigan and Cass avenues, near Campus Martius Park.

The western terminus of US 12 is located in Aberdeen, Washington. In the 1960s, a portion of US 12 was moved north to the town of Morton, when the Mossyrock Dam was built and flooded the towns of Kosmos and Riffe, along the Cowlitz River in Lewis County. A large portion of old, two-lane US 12 was replaced by Interstate 82 and Interstate 182 in the 1980s, between Yakima and the Tri-Cities, though the freeways are still cosigned with the US 12 designation. The old two-lane highway now bears the name Wine Country Road. The highway loosely follows the eastbound leg of the Lewis and Clark Expedition, between Wallula, Washington and Clarkston, Washington, thus being marked as part of the Lewis and Clark Trail. The east end of the highway in the state is at Clarkston, where the highway crosses the Snake River into Idaho at Lewiston.

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Wikipedia