Missouri Route 21

Route 21 is a highway in eastern Missouri. Its northern terminus is at Route 30 in Affton. Its southern terminus is at the Arkansas-Missouri state line (where it continues as Highway 115). In the St. Louis area, it is known as Tesson Ferry Road, which was named after the 19th century proprietor of the ferry across the Meramec River.^[1] Route 21 from the Meramec River to Route B, along with Route M, make up the Jefferson County Scenic Byway.^[2][3]

Route 21
Tesson Ferry Road
Route information
Maintained by MoDOT
Length	188 mi (303 km)
Existed	1922–present
Major junctions
South end	AR 115 at the Arkansas state line
Major intersections	US 160 in Doniphan US 60 near Van Buren Route 72 in Centerville Route 49 in Hogan Route 32 in Caledonia Route 47 in Mineral Point Route M / Route MM in Barnhart Route 141 in Paulina Hills I-270 in Concord US 50 / US 61 / US 67 in Concord
North end	Route 30 in Affton
Location
Country	United States
State	Missouri
Counties	Ripley, Carter, Reynolds, Iron, Washington, Jefferson, St. Louis
Highway system
Missouri State Highway System Interstate US State Supplemental
← Route 20 → Route 22

Improvements

Intersection of Highway 21 and 110, Right outside of De Soto, Missouri

The section through northern Jefferson County, Missouri was considered dangerous. As a result, the road was rerouted and built to freeway standards. Construction to reroute the highway to just south of Hillsboro was completed on December 15, 2008 and Route 21 is currently freeway standard from Route 141 to Highway B. Plans to extend the freeway south to De Soto have been approved, but funds are lacking to complete this part of the project.^[4]

Route description

Missouri Route 21 begins at the Arkansas state line, where it continues southward as Highway 115. As the highway enters Ripley County, it passes through the city of Doniphan, where it intersects US 160 and Route 142. Route 21 runs concurrent with US 160 for a short distance before separating east of Doniphan.^[5]

Continuing northward, Route 21 enters Carter County, where it meets US 60 near Van Buren. The highway briefly overlaps with US 60 before diverging and heading northeast into Reynolds County. In Reynolds County, Route 21 passes through Ellington, where it intersects Route 72 and continues northward toward Iron County.^[6]

Upon reaching Iron County, Route 21 enters Arcadia and Pilot Knob, where it intersects Route 221. The highway then continues northward, passing through Washington County and reaching Potosi, where it meets Route 8. Further north, Route 21 intersects Route 47 near Old Mines before entering Jefferson County.^[7]

In Jefferson County, Route 21 passes through De Soto, where it intersects Route 110. The highway continues northward, reaching Barnhart, where it meets Route M and Route MM. As Route 21 enters the St. Louis metropolitan area, it becomes a major arterial road known as Tesson Ferry Road, and passes through Concord and intersecting I-270. The highway then reaches its northern terminus at Route 30 in Affton.^[8]

Major intersections

County	Location	mi	km	Destinations	Notes
Ripley	​	0.000	0.000	AR 115 south – Pocahontas	Arkansas state line
	​	8.578	13.805	Route 142 west – Gatewood	Southern end of Route 142 overlap
	​	9.825	15.812	US 160 west – Alton	Southern end of US 160 overlap
	Doniphan	11.714	18.852	Route 142 east – Business District	Northern end of Route 142 overlap
	​	13.677	22.011	US 160 east – Poplar Bluff	Northern end of US 160 overlap
Carter	​	36.031	57.986	US 60 east – Poplar Bluff	Southern end of US 60 overlap
	​	45.608	73.399	US 60 west / Route 34 begins – Van Buren	Northern end of US 60 overlap; Southern end of Route 34 overlap
Reynolds	​	48.959	78.792	Route 34 east – Clearwater Dam, Piedmont	Northern end of Route 34 overlap
	Ellington	65.112	104.788	Route 106 west – Owls Bend, Eminence, Business District
	​	77.088	124.061	Route 72 west – Bunker	Southern end of Route 72 overlap
	​	85.027	136.838	Route 49 north – Black, Oates	Southern end of Route 49 overlap
Iron	​	98.252	158.121	Route 49 south – Annapolis	Northern end of Route 49 overlap
	Arcadia	107.967	173.756	Route 72 east	Northern end of Route 72 overlap
	Pilot Knob	110.072	177.144	Route 221 north
	​	119.405	192.164	Route 32 west	Southern end of Route 32 overlap
Washington	Caledonia	123.672	199.031	Route 32 east – Bismarck	Northern end of Route 32 overlap
	Potosi	135.913	218.731	Route 8 – Potosi, Leadwood
	Old Mines	142.085	228.664	Route 47 south – Bonne Terre	Southern end of Route 47 overlap
	​	147.011	236.591	Route 47 north – Richwoods	Northern end of Route 47 overlap
	Washington State Park	149.523	240.634	Route 104 east
		150.912	242.869	Route 104 west
Jefferson	​	161.379	259.714	Route 110 east
	Hillsboro	165.177	265.827	Route B begins / Business 21	Southern end of Route B overlap
	​	165.547	266.422	Route B north	Northern end of Route B overlap; southern end of freeway
	Hillsboro	167.854	270.135	Route A / Business 21
	​	169.236	272.359	Hayden Road
	​	172.575	277.733	Old Route 21 - Goldman
	​	175.162	281.896	Old Route 21 / Schenk Road
	Otto	177.733	286.034	Route MM / Route M – House Springs, Barnhart
	​	180.341	290.231	Old Route 21 - Shady Valley
	​	184.555	297.012	Old Route 21 - Meramec Heights	Southbound exit and northbound entrance
	​	185.469	298.483	Route 141 – Fenton, Arnold	Interchange; northern end of freeway
	​	185.864	299.119	Meramec Bottom Road
St. Louis	Concord	190.517	306.607	I-270 – Chicago, Memphis	I-270 exit 2
		191.717	308.539	US 50 / US 61 / US 67 (Lindbergh Boulevard)
	Affton	194.126	312.416	Route 30 (Gravois Road)
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Incomplete access

Hillsboro Business Spur

Route 21 Business
Location	Hillsboro, Jefferson County

1920s-era Missouri 21 marker

Business 21 follows the old alignment of Route 21 through the city of Hillsboro. It begins at the intersection of Route 21 and Highway B on the southern edge of the city, and continues north to the intersection of Route A and Old Route 21, where it ends. Business 21 is the only way one can now reach Route BB, as the rerouting of Route 21 bypasses the road.

See also

• U.S. Roads portal

• List of state highways in Missouri
• List of highways numbered 21