| Route 370 in Bridgeton|| 49.73 km|
| US 61 / US 67 in Arnold|
Fenton, Arnold, Valley Park, Chesterfield, Ballwin, Manchester, Town and Country, Twin Oaks
Jefferson County, Missouri, St. Louis County, Missouri
Highway 141 is a highway located in the western St. Louis metropolitan area. Its northern terminus is at Route 370 in Bridgeton; its southern terminus is at U.S. Route 61/U.S. Route 67 in Arnold, in Jefferson County. The northern stretches of the highway are often referred to as the Maryland Heights Expressway or the Earth City Expressway.
Missouri Route 141 Wikipedia
The section of Route 141 between Interstate 64 and the St. Louis County/Jefferson County line was upgraded to six lanes in a project completed in 2003. The section in Jefferson County is four lanes. For the majority of its duration, 141 is a divided highway with four to eight lanes.
As of August, 2012, a new six-lane realignment opened between Ladue Road and Page Avenue (Route 364), with interchanges at Ladue, Olive (Route 340), and Page. The section between Page and Olive (tentatively titled the Page-Olive Connector), which was constructed by St. Louis County has been turned over to the Missouri Department of Transportation and designated as Route 141. Maryland Heights Expressway (the section from Page north to I-70) and Earth City Expressway (the section from I-70 north to its terminus at Route 370) have also been designated as 141. As such, Route 141 now runs from US 61/67 in Arnold to Route 370 in Bridgeton.