sentences:  The part north of Dunn Road, where Route 77 turned off to access the bridge, was initially Route M and later Route 140.Route 77 was later extended at the south end to the Jefferson Barracks Bridge, and US 61 and US 66 were realigned onto the bypass, leaving only this extension as Route 77.That portion became part of US 50 when it was moved onto the bridge, and US 67 eventually replaced Route 140.