Louisiana Highway 21

Louisiana Highway 21
Louisiana Highway 21
Route information
	Maintained by Louisiana DOTD
Length	52.1 mi (83.8 km)
Existed	1955 renumbering–present
Major junctions
South end	LA 22 / LA 1077 in Madisonville
	I-12 near Covington; US 190 in Covington; LA 36 in Covington; LA 59 near Waldheim; LA 40 near Bush; LA 41 in Bush; LA 16 in Sun; LA 10 in Bogalusa;
North end	MS 35 at Mississippi state line
Location
Country	United States
State	Louisiana
Highway system
	Louisiana State Highway System; Interstate; US; State; Scenic;

Louisiana Highway 21 (LA 21) is a state highway in Louisiana that serves St. Tammany and Washington Parishes. It spans 51.76 miles (83.30 km) and is signed north and south.