U.S. Route 18 in Iowa

From the AARoads Wiki: Read about the road before you go
Jump to navigation Jump to search

U.S. Highway 18

US 18 highlighted in red
Route information
Maintained by Iowa DOT
Length311.750 mi[1] (501.713 km)
ExistedNovember 11, 1926[2]–present
HistoryPrimary Road 19 from 1920–1926[3]
National Parks Pike registered in 1920[4]
Major junctions
West end US 18 near Canton, S.D.
Major intersections
East end US 18 / WIS 60 at McGregor
CountryUnited States
Highway system
Iowa 17 US 20

U.S. Highway 18 (US 18) is the northernmost east–west United States Numbered Highway in the state of Iowa. As with all state highways in Iowa, it is maintained by the Iowa Department of Transportation (Iowa DOT). It enters the state by crossing the Big Sioux River between Inwood and Canton, South Dakota. It travels about 312 miles (502 km) and connects Spencer, Mason City, and Charles City. The highway leaves the state via the Marquette–Joliet Bridge over the Mississippi River at Marquette. Prior to becoming a U.S. Highway, the route US 18 follows was known as Primary Road No. 19 and the National Parks Pike.

Route description

US 18 begins at the Big Sioux River approximately two miles (3.2 km) east of Canton, South Dakota. It runs easterly through rural Lyon County, in the northwestern corner of the state. At Inwood, it meets Iowa Highway 182 (Iowa 182), which provides access to Sioux Falls, South Dakota, via Iowa 9 and South Dakota Highway 42. US 18 turns south at Inwood and heads into Sioux County. The highway crosses the Rock River on its way toward Rock Valley and Hull. West of Hull, at Perkins, US 18 juts to the south along US 75 before turning east again closer to Hull. The highway continues east toward Sheldon.[5]

As it crosses into O'Brien County on the western edge of Sheldon, US 18 intersects Iowa 60 Business (Iowa 60 Bus.). The two routes head east toward a diamond interchange with Iowa 60 on the eastern side of town where the business loop ends. The highway roughly parallels the Dakota, Minnesota and Eastern Railroad (DM&E Railroad). In Sanborn, US 18 is briefly overlapped by US 59, which joins from the north and leaves to the south. Continuing east, it passes through Hartley and then enters Clay County. North of Spencer, it intersects US 71 and the two routes head south together through town. On the south side of Spencer, the two routes come to a T intersection and each route heads in the opposite direction—US 18 to the east and US 71 to the west.[5]

East of Spencer, US 18 passes through Ruthven in Palo Alto County. Between Ruthven and Emmetsburg, it is joined by Iowa 4 from the north. The two routes split again in Emmetsburg as Iowa 4 heads south. US 18 continues east, briefly heading south to enter Cylinder. The route curves back to the east at the DM&E Railroad line. An intersection with Iowa 15 near Whittemore marks the Palo Alto–Kossuth county line. Iowa 15 follows US 18 for one mile (1.6 km) before it splits away to the north. On the northern edge of Algona, the highway meets US 169. At the eastern county line, shared with Hancock County, is an intersection with Iowa 17, which marks that route's northern end.[5]

In Hancock County, the route passes through Britt before meeting US 69 one mile (1.6 km) west of Garner; the two highways split in Garner. East of Garner, the route takes a north-northeasterly path as it goes through Ventura and skirts the northern shore of Clear Lake. Near the northeastern shore of the lake, it enters the city of Clear Lake, where it meets Interstate 35 (I-35). Iowa 122 and US 18 Bus. head east from the interchange with the Interstate. US 18 traffic follows southbound I-35 for four miles (6.4 km). Iowa 27, the Avenue of the Saints highway, which had hitherto followed I-35 southbound now follows US 18 eastbound. The two routes, now on a four-lane, controlled-access highway, follow a path which passes to the south of Mason City. They meet US 65 and US 18 Bus. at exit 186.[5]

US 18/US 218/Iowa 27 pass a wind farm near Charles City

At the Floyd county line, US 18 and Iowa 27 become a limited-access road and angle slightly to the northeast, passing Rudd. At Floyd, the two routes are joined by US 218. The three routes head south along a bypass of Charles City. They intersect Iowa 14 on the western side of town and take a 90-degree curve to the east. At exit 218 of the expressway, US 18 leaves US 218 and Iowa 27, which continue southeastward toward Cedar FallsWaterloo. US 18 briefly heads north into Charles City with US 218 Bus. The two routes meet the northern end of Iowa 14, and US 18 splits away to the east to cross the Cedar River.

Heading east again, the route enters Chickasaw County and passes through Bassett on its way to New Hampton. It meets US 63 at a four-lane bypass on the western side of town. The two routes head south for eight miles (13 km), splitting at the mile 196 interchange which is also the eastern end of Iowa 346. The route turns to travel due east through Fredericksburg.[5]

US 18 crosses into Wisconsin via the Marquette–Joliet Bridge

Continuing due east, US 18 does not enter another community for 20 miles (32 km) until it reaches West Union in Fayette County. In West Union, it intersects Iowa 150. East of town, it crosses into the Driftless Area, an area that was untouched by glaciation during the last ice age. The route turns to the northeast to through Clermont and then to the north to meet US 52 at Postville in southern Allamakee County. The two routes head east through Postville and turn south into Clayton County. Near Froelich, US 52 leaves to the south toward Dubuque. Heading to the northeast toward McGregor and Marquette, its business loop goes through the towns while the mainline skirts around them. The business loop rejoins the mainline at the foot of the Marquette–Joliet Bridge, which spans the Mississippi River.[5] US 18 continues east into Wisconsin with State Trunk Highway 60, which begins at the state line.[6]


Before it and the rest of the U.S. Numbered Highway System were designated on November 11, 1926, US 18 was known by two names in the state. It was first known as Primary Road No. 19, which was assigned to the route when the Iowa State Highway Commission published its first state highway map in 1919.[7] The route was also called the National Parks Pike, which began at Yellowstone National Park and ended in Madison, Wisconsin, encompassing all of Primary Road No. 19 in the state. The pike was registered with the on April 29, 1920.[4] The National Parks Pike name fell into disuse after the highway became US 18.[8]

By 1927, a significant portion of the route was paved, while the remainder was graveled. All of O'Brien County and 80 miles (130 km) between Algona and Charles City were paved.[9] In seven years, the gap between O'Brien County and Algona was finished which created 160 miles (260 km) of continuous pavement. During those same seven years, the route from West Union to the Mississippi River and all of Primary Road No. 59, which included the seven-mile-long (11 km) overlap of US 18 near New Hampton were paved.[10] Primary Road No. 59 is now known as US 63. By the start of World War II, the only remaining section of US 18 that was not paved was an 11-mile (18 km) section west of Rock Valley in Sioux County.[11] That last section would not be completed for another 10 years.[12]

US 18 passing through McGregor in 1975

Prior to 1932, the only way vehicles traveling US 18 could cross the Mississippi River was by ferry. That changed in when identical suspension bridges were built to cross the river between Marquette and Prairie du Chien, Wisconsin. Built in 1931–1932, each bridge was 450 feet (140 m) long, crossed a main channel of the river, and were divided by a 2,000-foot-long (610 m) island causeway. The first car to cross the bridges did so on March 7, 1932. Users of the bridge had to pay a toll until July 15, 1954. The bridges remained in use for another 20 years, when they were replaced by the Marquette–Joliet Bridge.[13] In 1988–1989, a bypass was built around McGregor so US 18 could connect directly to the Marquette–Joliet Bridge. A short road had previously provided access to and from the bridge. The old alignment of the route became US 18 Bus.[14]

Over the late 1990s, construction began on the Avenue of the Saints corridor near Mason City. A new controlled-access facility was built south of the city east to Rudd.[5] On December 5, 1999, this section of freeway opened and US 18 was realigned onto the new road. The old alignment became Iowa 122. By the end of the next year, the four-lane expressway was extended to Charles City.[15] By 2003, an expressway carrying US 63 was built around New Hampton. US 18 was rerouted onto the expressway and the western end of Iowa 24 was moved to the US 63/US 18 interchange.[16]

Major intersections

Big Sioux River0.0000.000
US 18 west – Canton
Continuation into South Dakota
South Dakota–Iowa state line

Iowa 182 north to Iowa 9
SiouxLincoln Township24.85339.997
US 75 north – Rock Rapids
Western end of US 75 overlap
US 75 south – Sioux Center
Eastern end of US 75 overlap

Iowa 60 Business south (2nd Avenue)
Western end of Iowa 60 Business overlap

Iowa 60 / Iowa 60 Business ends – Worthington, Minn., Sioux City
Eastern end of Iowa 60 Business overlap
US 59 north – Worthington, Minn.
Western end of US 59 overlap
Franklin Township53.80286.586
US 59 south – Primghar
Eastern end of US 59 overlap
US 71 north – Milford
Western end of US 71 overlap
US 71 south – Storm Lake
Eastern end of US 71 overlap
Palo AltoHighland Township94.160151.536 CR N20 – RuthvenFormer Iowa 341
97.317156.617 CR N28 – AyrshireFormer Iowa 314
Emmetsburg Township101.306163.036
Iowa 4 north – Graettinger
Western end of Iowa 4 overlap
Iowa 4 south (Broadway Street) – Pocahontas
Eastern end of Iowa 4 overlap
Palo AltoKossuth
county line
Fern ValleyFairfield
Lotts CreekWhittemore
township quadripoint
Iowa 15 south – West Bend
Western end of Iowa 15 overlap
KossuthLotts CreekWhittemore
township line
Iowa 15 north – Fenton
Eastern end of Iowa 15 overlap
Algona130.144209.446 US 169 – Algona, Bancroft
county line
township line
Iowa 17 south – Corwith
HancockBritt152.452245.348 CR R35 – Crystal Lake, KanawhaFormer Iowa 111
153.185246.527Diagonal StreetFormer Iowa 424
Garfield Township160.877258.906
US 69 north – Forest City
Western end of US 69 overlap
US 69 south – Belmond
Eastern end of US 69 overlap
Cerro GordoClear Lake172.233277.182N. 8th StreetFormer Iowa 107

I-35 north / Iowa 27 north – Minneapolis

US 18 Bus. east / Iowa 122 east – Mason City
Western end of I-35 / Iowa 27 overlap
176.204283.573193 CR B35 (4th Avenue South)Former Iowa 106
Lake Township178.210–
I-35 south – Des Moines
Eastern end of I-35 overlap
183.163294.772183 Eisenhower Avenue — Airport
Mason City186.409299.996186

US 65 / US 18 Bus. west – Downtown Mason City, Rockwell
Portland Township190.460306.516190 CR S56 (California Avenue)
Cerro GordoFloyd
county line
PortlandRock Grove
township line
195.596314.781195 CR S70 – Nora Springs
FloydRudd Township203.141326.924 CR B30 – RuddFormer US 18
US 218 north / CR T44 – Floyd
Northern end of US 218 overlap
Floyd Township212.687342.287212
US 218 Bus. / CR B35 – Charles City
Saint Charles Township214.811345.705214 Iowa 14 – Charles City, Greene
Charles City218.023–

US 218 south / Iowa 27 south – Waterloo

US 218 Bus. begins
Eastern end of US 218 and Iowa 27 overlaps; southern end of US 218 Business overlap
219.311352.947Old Highway RoadFormer US 218

US 218 Bus. north / Iowa 14 south
Northern end of US 218 Business overlap
ChickasawChickasaw Township231.617372.751 CR V14 – IoniaFormer Iowa 393
New Hampton237.701–

US 63 north / Iowa 24 east – New Hampton, Lime Springs
Western end of US 63 overlap
New Hampton Township240.338386.787201225th Street – New Hampton
Dresden Township244.457–

US 63 south / Iowa 346 west – Nashua, Waterloo
Eastern end of US 63 overlap
FayetteBethel Township258.905416.667 CR V68 – WaucomaFormer Iowa 193
West Union270.469435.278
Iowa 150 to Iowa 56 / River Bluffs Scenic Byway – Fayette, Calmar
Western end of River Bluffs Scenic Byway overlap
CR W42 / River Bluffs Scenic BywayEastern end of River Bluffs Scenic Byway overlap
Clermont CR B40 / River Bluffs Scenic BywayWestern end of River Bluffs Scenic Byway overlap
CR B60 / River Bluffs Scenic BywayEastern end of River Bluffs Scenic Byway overlap
ClaytonNo major intersections
AllamakeePost Township287.042461.949
US 52 north – Calmar
Western end of US 52 overlap
Iowa 51 north (N. Lawler Street)
CR B38 (S. Maple Street) / Driftless Area Scenic Byway
ClaytonGiard Township303.396488.269
US 52 south / River Bluffs Scenic Byway – Guttenberg
Eastern end of US 52 overlap; western end of River Bluffs Scenic Byway overlap
Mendon Township307.864495.459

US 18 Bus. east / Iowa 76 north – McGregor

US 18 Bus. west / Iowa 76 / Great River Road / River Bluffs Scenic Byway – Marquette, McGregor
Mississippi River311.750501.713Marquette–Joliet Bridge; Iowa–Wisconsin state line

US 18 east / WIS 60 east – Prairie du Chien
Continuation into Wisconsin
1.000 mi = 1.609 km; 1.000 km = 0.621 mi

See also


  1. ^ a b "Road Network (Portal)" (ESRI shapefile). Ames: Iowa Department of Transportation. April 9, 2021. Retrieved April 17, 2021.
  2. ^ Bureau of Public Roads & American Association of State Highway Officials (November 11, 1926). United States System of Highways Adopted for Uniform Marking by the American Association of State Highway Officials (Map). 1:7,000,000. Washington, DC: United States Geological Survey. OCLC 32889555. Retrieved November 7, 2013 – via Wikimedia Commons.
  3. ^ Official Auto Trails Map (Map). 1:1,081,344. Rand McNally. 1921. p. 330-331.
  4. ^ a b "Iowa Registered Routes". Iowa Department of Transportation. Retrieved September 15, 2011.
  5. ^ a b c d e f g h Transportation Map (PDF) (Map). Iowa Department of Transportation. 2011. Retrieved September 12, 2011.
  6. ^ Morrison, Jeff (December 9, 2007). "Iowa termini of US 18". Iowahigwhayends.net. Retrieved September 14, 2011.
  7. ^ Iowa State Highway Map (PDF) (Map). Iowa State Highway Commission. 1919. Retrieved September 15, 2011.
  8. ^ Iowa Registered Highway Routes 1914–1925 (PDF) (Map). Iowa Department of Transportation. 1986. Retrieved September 15, 2011.
  9. ^ Iowa State Highway Map (PDF) (Map). Iowa State Highway Commission. 1927. Retrieved September 15, 2011.
  10. ^ Iowa State Highway Map (PDF) (Map). Iowa State Highway Commission. June 1934. Retrieved September 15, 2011.
  11. ^ Iowa State Highway Map (PDF) (Map). Iowa State Highway Commission. 1939. Retrieved September 15, 2011.
  12. ^ Iowa State Highway Map (PDF) (Map). Iowa State Highway Commission. 1950. Retrieved September 15, 2011.
  13. ^ Rodenburg, Lucy. "The old Suspension Bridge provided the river crossing from 1932-1974". North Iowa Times. McGregor, Iowa. Archived from the original on August 16, 2011. Retrieved September 15, 2011.
  14. ^ Iowa State Highway Map (PDF) (Map). Iowa Department of Transportation. 1990. Retrieved September 15, 2011.
  15. ^ "Avenue of the Saints". Iowa Department of Transportation. Archived from the original on February 6, 2016. Retrieved September 16, 2011.
  16. ^ Iowa State Highway Map (PDF) (Map). Iowa Department of Transportation. 2003. Retrieved September 16, 2011.

External links

U.S. Route 18
Previous state:
South Dakota
Iowa Next state: