Louisiana Highway 21

Louisiana Highway 21
Route information
Maintained by Louisiana DOTD
Length:	51.76 mi (83.30 km)
Existed:	1955 renumbering – present
Major junctions
South end:	LA 22 / LA 1077 in Madisonville
	I-12 in Covington US 190 in Covington LA 36 in Covington LA 59 south of Waldheim LA 40 south of Bush LA 41 in Bush LA 16 in Sun LA 10 in Bogalusa
North end:	MS 35 at state line
Highway system
Louisiana Highway System Interstate US State ← LA 20 LA 22 →

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 bannered north/south.

Route description

From the south, LA 21 begins at an intersection with Louisiana Highway 22 and Louisiana Highway 1077 in Madisonville, where LA 21 assumes the trajectory of LA 1077 and heads northeast. LA 1077 branches to the northwest before LA 21 intersects Interstate 12. From south of I-12 and until joining US 190 Business on 21st Avenue in Covington, LA 21 is multilane, in places divided by a median or by a center turn lane, with some control of access.

Improved, multilane, divided section of LA 21 between Covington and Madisonville. See also list of numbered highways in Louisiana.

Through most of Covington LA 21 is in a mostly two-lane undivided concurrency with US 190 Business, which returns to U.S. Route 190 on the east side of Covington—an area known as Claiborne Hill. After intersecting US 190 and before leaving Covington cosigned as Military Road, LA 21 absorbs LA 36 and continues northeastward, absorbing LA 59 and entering a brief concurrency with Louisiana Highway 40 in Bush for less than one mile (1.6 km). Between Bush and Sun, LA 21 widens to a four lane, divided highway after merging Louisiana Highway 41, continuing due north from the merge. In Sun LA 21 absorbs LA 16 and continues northward to Bogalusa, where LA 21 intersects LA 10. LA 21 then runs north through Varnado and Angie before becoming Mississippi Highway 35 at the state line.

Major intersections

Parish	Location	mi	km	Destinations	Notes
St. Tammany	Madisonville			LA 22 (Mulberry Street) / LA 1077 south (Main Street) – Fairview Riverside State Park, Maritime Museum	south end of LA 1077 overlap
	​			LA 1077 north to I-12	north end of LA 1077 overlap
	​			I-12 – Hammond, Slidell	I-12 exit 59
	Covington			US 190 Bus. west (West 21st Avenue)	south end of US 190 Bus. overlap
				US 190 west to I-12 – Mandeville, New Orleans	interchange
				US 190 Bus. east to US 190 – Franklinton	north end of US 190 Bus. overlap
	​			LA 36 east – Abita Springs
	​			LA 1082 north
	​			LA 59 south – Abita Springs
	​			LA 1084 east
	Waldheim			LA 1083 south	south end of LA 1083 overlap
				LA 1083 north	north end of LA 1083 overlap
	​			LA 40 west	south end of LA 40 overlap
	​			LA 40 east	north end of LA 40 overlap
	​			LA 41 south
	Sun			LA 16 west
Washington	​			LA 1075 north
	​			LA 3124 north – Bogalusa Central Business District
	Bogalusa			LA 10
	​			LA 436 east
	​			LA 436 – Pine, Franklinton
	Varnado			LA 436-1 east
	Angie			LA 1071 east
				LA 438 west	south end of LA 438 overlap
				LA 438 east	north end of LA 438 overlap
	​			MS 35 north – Columbia	Mississippi state line
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

External links

• LADOTD Map of State Highways
• Louisiana State Highway Log