MP: 0 Location: E Heron St and S H St, Aberdeen 2,483 Miles to Detroit at the western terminus of US-12. Also the western terminus of the only fully cross-state highway in Washington. It begins with a sign to turn back to the 101 couplet and head back north on it   MP: .23 Location: … Continue reading U.S. Route 12, US-101 to SR 107