U.S. Route 20 in Iowa

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U.S. Highway 20 marker

U.S. Highway 20
Route information
Maintained by Iowa DOT
Length: 301.429 mi[1] (485.103 km)
Existed: 1926 – present
Major junctions
West end: I-129 / US 20 / US 75 at South Sioux City, NE
East end: US 20 at East Dubuque, IL
Highway system
US 18 Iowa 21

U.S. Highway 20 in Iowa is a major east–west artery which runs across the state, separating the northern third of Iowa from the southern two-thirds. It enters Iowa from Nebraska, concurrent with Interstate 129 and U.S Route 75, crossing the Missouri River at Sioux City. US 20 runs in a more-or-less straight line across Iowa, paralleling 42° 27' N. It leaves Iowa in Dubuque by crossing the Mississippi River into Illinois. The state of Iowa is in the process of upgrading US 20 into a four-lane divided highway for its entire length in Iowa.

Route description[edit]

Western Iowa[edit]

US 20 enters Iowa on the Sergeant Floyd Memorial Bridge, which also carries I-129 and US 75, over the Missouri River. Almost immediately upon landing in Iowa, there is an interchange with I-29, at which I-129 ends. Continuing east, US 20 and US 75 run together around the southern and eastern sides of Sioux City. The two routes split and US 20 continues to the east. US 20's business loop of Sioux City begins at the US 75 interchange as well.

East of Sioux City, U.S. Highway 20 continues as an expressway until Moville. From there, it is a rural, two-lane highway with only a short expressway segment just south of Holstein, that is briefly concurrent with U.S. Route 59. From US 59, it is about 18 miles (29 km)[2] until US 20 has another four-lane segment, starting about one mile west of an interchange with U.S. Route 71 and Iowa Highway 471, just north of Early. This final stretch of two-lane road will be upgraded to four-lane between 2016 and 2018.[3] From this point until an interchange with Iowa Highway 4 northwest of Rockwell City is the newest section of four-lane, which opened in November 2012.[4] This new roadway passes to the north of Sac City and Lytton, and has another interchange with the realigned route of U.S. Route 71 northeast of Sac City, but mostly has at-grade intersections, including County M54 into Sac City and N28 into Lytton.

Central Iowa[edit]

East of Iowa 4, and extending to the former beginning of the four-lane expressway northeast of Moorland (now an interchange with County D36), is a 4-lane section which opened in December 2010, and bypasses Rockwell City to the north. US 20 continues until just south of Highview, when it becomes a full interstate-standard freeway. The expressway south of Fort Dodge has interchanges with U.S. Route 169 and Webster County Route P59. East of Fort Dodge, US 20 overlaps with Iowa Highway 17 for 4.5 miles (7.2 km), ending at Webster City. Near Williams, US 20 intersects Interstate 35. Beginning at the interchange with U.S. Route 65 is a section of four-lane freeway which, when completed, shaved nearly 16 miles (26 km) off of US 20's length. Prior to 2003, US 20 joined U.S. Route 65 north through Iowa Falls and then east towards Ackley and Parkersburg before heading south again to the freeway with Iowa Highway 14. The bridge crossing the Iowa River near Steamboat Rock is a launched steel I-girder bridge, the first of its kind in the United States.[5] The bridge was designed to cross the old-growth woodland of the Iowa River valley with minimal impact.

Eastern Iowa[edit]

U.S. Highway 20 continues east towards Cedar Falls where it overlaps Iowa Highway 58 for just over 1 mile (1.6 km). The western junction of Iowa 58 (Hudson Road) connects traffic to the University of Northern Iowa while the eastern junction of Iowa 58 is also the western junction of Iowa Highway 27, the Avenue of the Saints. Another mile east, in Waterloo, US 20 intersects U.S. Route 63 (Sergeant Road). On the southeast side of Waterloo, Interstate 380 joins US 20/IA 27 for 6 miles (9.7 km) before exiting with Iowa 27 south towards Cedar Rapids.

U.S. 20 continues as a freeway east of Waterloo. It intersects Iowa Highway 150 at Independence and Iowa Highway 13 at Manchester, as well as junctioning a number of county roads serving smaller communities. Approximately 21 miles (34 km) between Independence and Manchester go over a terminal moraine and enter the Driftless Area, a region it will not exit until reaching Stockton, Illinois.

An overlook of a city in the foreground and a river running through the middle of the picture. Three bridges cross the river.
U.S. Highway 20 crosses the Mississippi River at Dubuque using the Julien Dubuque Bridge.

At Delaware, US 20 changes from a freeway to an expressway with at-grade intersections; however, there are many interchanges where US 20 meets major roads, mostly at the villages and towns along US 20's route. US 20 serves Earlville, Dyersville (passing near the Field of Dreams filming site), Farley, Epworth, and Peosta before entering Dubuque. US 20 remains at least four lanes through Dubuque, but there are several stoplights along the route, particularly on the western edge of the city. There is a brief controlled-access section where the highway descends into the Mississippi River valley. Near the river, Locust Street connects US 20 with U.S. Highway 52, U.S. Highway 61, and U.S. Highway 151, which have entered the city from the south as an expressway and continue northward as a freeway. US 20 crosses from Iowa into Illinois via the Julien Dubuque Bridge.


U.S. Highway 20 was designated in Iowa on October 16, 1926. The designation created a single route number for drivers to follow across the state from Sioux City to Dubuque; previously, three route numbers were used.

It is possible to drive most of US 20's former two-lane alignment from Early to Dubuque. Most of this routing (with the exception of Iowa Highway 57 from US 65 to Cedar Falls) is now under city and county control, but most of the guide signs remain from when US 20 followed this route. From Moorland, the highway's former alignment is U.S. Highway 20 Business through Fort Dodge. At Webster County Route P59, it continues on Webster County Route D20. The road changes designations several times between this point and Iowa Falls, but its route is very clear. It follows US 65 north out of Iowa Falls to the junction of Iowa 57, then follows 57 to Cedar Falls. At Cedar Falls, the former alignment continues on US 218 to Broadway Street; through Waterloo, it follows Broadway to Franklin Street to Dubuque Road. Beyond Waterloo, the designation of the road again changes several times, but the route to follow remains clear. Between Dyersville and Farley, US 20 follows its historic alignment. At Farley, the former alignment follows Old Highway Road into Dubuque.

Expansion project[edit]

The first segment of US 20 in Iowa to become four lanes was a short expressway segment east of Moville, which opened in 1958. Another short expressway segment in the Dubuque area opened in 1959. The rest of the expressway from Sioux City to Moville opened in 1964. By 1979 the Sioux City bypass was complete, as well as the section from Iowa 17 to Interstate 35, and the section from Independence to Delaware. By the end of the 1980s, the four-lane portions of US 20 ran from Coalville (near Fort Dodge) to Interstate 35 and from Waterloo to Dubuque.

During the 1990s little work was done to the route. It was extended westward to US 169 in 1991, and eastward to US 65 the same year, though initially the section from I-35 to US 65 was only two lanes. The new, semi-controlled section in Dubuque opened in 1996. Work began to accelerate in 2000, with the section between Interstate 35 and U.S. Highway 65 becoming four lanes that year. The segment from Iowa 14 to Cedar Falls also opened in 2000. By 2003, the highway was complete from Fort Dodge to Dubuque.

Paving work between Iowa Highway 4 and Moorland was completed in 2010 and the stretch was opened in December 2010. In November 2012, the 4-lane highway opened between Iowa 4 near Rockwell City and US 71 at Early, Iowa.[6]


As of January 2014, around 40 miles (64 km) of US 20 remained two lane, between Early and Moville. Local leaders were lobbying for the remaining estimated cost of $375 million to complete the project.[4]

In November 2015, it was announced that the final forty miles of US 20 between Early and Moville will be upgraded to four lanes at an estimated cost of $240 million. The funding came from the state's gas tax increase. Construction on the final piece should be done by 2018.[3]

Exit list[edit]

County Location mi[1] km Exit[7] Destinations Notes
Missouri River 0.000 0.000 I-129 west / US 20 west / US 75 south – South Sioux City Continuation into Nebraska
Sergeant Floyd Memorial Bridge; NebraskaIowa state line
Woodbury Sioux City 0.286 0.460 1
I-29 / I-129 ends / US 75 Business north – Sioux City, Council Bluffs, South Sioux City
Eastern end of I-129 overlap; signed as exits 1A (north) and 1B (south); no exit number westbound
1.741 2.802 1 Lakeport Road
2.859 4.601 2 Sunnybrook Drive
3.407 5.483 3 Morningside Avenue
Woodbury Township 4.529 7.289 4
US 75 north / US 20 Business west (Gordon Drive) – Le Mars
Eastern end of US 75 overlap
Moville 17.393 27.991 Iowa 140 north / CR K64 south – Kingsley, Climbing Hill
Correctionville 31.985 51.475 Iowa 31 south – Smithland Western end of Iowa 31 overlap
32.212 51.840 Iowa 31 north – Correctionville, Washta Eastern end of Iowa 31 overlap
Ida Holstein 44.682 71.909 US 59 north – Holstein Western end of US 59 overlap
Logan Township 46.093 74.179 US 59 south – Ida Grove Eastern end of US 59 overlap
Sac Eureka Township 57.769 92.970 Iowa 110 north – Schaller, Storm Lake
Boyer Valley Township 65.250 105.010 71 US 71 north / Iowa 471 south – Storm Lake, Lake View Western end of US 71 overlap
Cedar Township 75.765 121.932 82 US 71 south / CR N14 north – Sac City Eastern end of US 71 overlap
Calhoun Twin Lakes Township 90.977 146.413 96 Iowa 4 – Rockwell City, Pocahontas
Webster Fulton Township 110.599 177.992 116
US 20 Business east / CR D36 – Moorland, Fort Dodge
US 20 Business only signed eastbound
Elkhorn Township 115.882 186.494 121 US 169 – Fort Dodge, Humboldt Access to Trinity Regional Medical Center
Pleasant Valley Township 119.032 191.563 124
US 20 Business west / CR P59 – Fort Dodge, Coalville
US 20 Business only signed westbound
Hamilton Freedom Township 130.247 209.612 136 Iowa 17 north / CR R21 – Eagle Grove, Stratford Western end of Iowa 17 overlap
Webster City 134.795 216.932 140 Iowa 17 south – Webster City, Stanhope Eastern end of Iowa 17 overlap, access to Van Diest Medical Center
Independence Township 139.761 224.924 145 CR R38 – Kamrar
Liberty Township 143.770 231.375 149 US 69 – Jewell, Belmond
Rose Grove Township 147.405 237.225 153 I-35 – Des Moines, Mason City Signed as exit 153A (south) and 153B (north)
149.858 241.173 155 CR R77 – Williams
Hardin Buckeye Township 156.774 252.303 162 CR S27 – Alden, Buckeye
Ellis Township 163.114 262.507 168 US 65 – Iowa Falls, Hubbard Access to Ellsworth Municipal Hospital
Jackson Township 176.270 283.679 175 CR D35 – Eldora, Owasa, Steamboat Rock
Clay Township 181.933 292.793 181 CR S56 – Ackley, Eldora
Grundy Shiloh Township 182.017 292.928 187 CR T19 – Wellsburg
township line
190.026 305.817 208 Iowa 14 – Parkersburg, Grundy Center
Dike 197.041 317.107 215 CR T55 – Dike, New Hartford
GrundyBlack Hawk
county line
GrantBlack Hawk
township line
202.089 325.231 220 CR D18 – Cedar Falls
Black Hawk Cedar FallsHudson
city line
205.593 330.870 224 Iowa 58 south (Hudson Road) – Hudson, University of Northern Iowa, UNI-Dome Western end of Iowa 58 overlap
206.684 332.626 225
Iowa 27 north (Avenue of the Saints) / Iowa 58 north – Cedar Falls, Airport
Eastern end of Iowa 58 overlap; western end of Iowa 27 overlap
Waterloo 208.744 335.941 227 US 63 (Sergeant Road) – Hudson
210.276 338.406 229 Ansborough Avenue
211.784 340.833 230 Iowa 21 south (Hawkeye Road) – Dysart
213.566 343.701 232
I-380 north / US 218 – Waterloo, La Porte City Western end of I-380 overlap; exit numbers follow I-380
Evansdale 214.374 345.002 70 River Forest Road
216.642 348.652 68 Evansdale Drive – Elk Run Heights
Poyner Township 218.550 351.722 66 CR V49 – Raymond, Gilbertville
219.985 354.032 65
I-380 south / Iowa 27 south (Avenue of the Saints)
Eastern end of I-380 and Iowa 27 overlaps; exit numbers follow US 20
Fox Township 221.496 356.463 240 CR V51 – Dunkerton, La Porte City
Buchanan Westburg Township 226.927 365.204 245 CR V65 – Jesup
Independence 233.918 376.455 252 Independence
235.417 378.867 254 Iowa 150 – Independence, Vinton
Winthrop 242.511 390.284 261 CR W40 – Quasqueton, Winthrop
Middlefield Township 247.952 399.040 266 Iowa 187 north – Masonville, Lamont
Delaware PrairieMilo
township line
256.449 412.715 275 Iowa 13 – Manchester, Central City
Manchester 258.394 415.845 277 CR D5X – Manchester
Delaware 263.459 423.996 282 Iowa 38 – Delaware, Monticello
township line
267.176 429.978 285 CR X35 – Earlville
Dyersville 292 CR X49 – Dyersville Interchange opened in 2016
Dubuque 275.273 443.009 294 Iowa 136 – Dyersville, Cascade
Farley 281.439 452.932 300 CR Y13 – Farley
Epworth 285.250 459.065 304 CR Y17 – Epworth
Peosta 289.425 465.784 308 CR Y21 – Northeast Iowa Community College
Dubuque 297.044 478.046 Iowa 32 north (Northwest Arterial) – Asbury
Grandview Avenue, Fremont Avenue
300.236 483.183 Hill Street, Bryant Street
300.929 484.298 Locust Street (Iowa 946) to US 52 / US 61 / US 151
Mississippi River 301.429 485.103 Julien Dubuque Bridge; Iowa–Illinois state line
US 20 east – Rockford Continuation into Illinois
1.000 mi = 1.609 km; 1.000 km = 0.621 mi


  1. ^ a b "2012 Volume of Traffic on the Primary Road System of Iowa" (PDF). Iowa Department of Transportation. January 1, 2012. Retrieved July 17, 2013. 
  2. ^ Google (April 17, 2009). "U.S. Route 20 in Iowa" (Map). Google Maps. Google. Retrieved April 17, 2009. 
  3. ^ a b "Final Piece of US 20 Four-Lane Highway To Be Finished by 2018". Retrieved November 20, 2015. 
  4. ^ a b Dreeszen, Dave (January 26, 2014). "Local leaders to lobby for Highway 20 funding". Sioux City Journal. Retrieved April 10, 2014. 
  5. ^ Iowa Department of Transportation (2003). "The US 20 Iowa River Bridge — A Launched Steel I-Girder Bridge". Archived from the original on May 23, 2009. Retrieved October 30, 2009. 
  6. ^ Local leaders to lobby for Highway 20 funding. Sioux City Journal. January 26, 2014.
  7. ^ Iowa Department of Transportation (2012). State of Iowa Transportation Map (PDF) (Map). Ames: Iowa Department of Transportation. Retrieved May 25, 2012. 

External links[edit]

Route map: Google

KML is from Wikidata
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