Sioux City: Highway Chronology

The area covered in this map is approximately that of the Sioux City inset on the state map. The Woodbury/Plymouth county line is just below the north edge of the box. These maps also include all of South Sioux City NE, Dakota City NE, and Sergeant Bluff. Each year's box lists all the changes that happened between that map and the next. Four-lane roads are shown as thicker lines, although Gordon Drive, Lewis Boulevard, and the four-lane roads in Nebraska other than I-129 have at-grade intersections.

IA 12/23/34 triplex route: 4th St, Westcott St, 2nd St/Fairmount St (EB) and 1st St (WB), then south to intersection of Fairmount/Correctionville (IA 12 before 1924) End 5: Probably Court at 4th. IA 12/29 may or may not have been duplexed a block with it. End 12/29: Probably 5th at Court, one block north of 5's end October 16, 1926: US 20 replaces IA 23 east of downtown, IA 34 in downtown, and NE 1; US 75 replaces IA 5 and IA 12 south of downtown; US 73 replaces NE 5 to S. Sioux City; IA 141 replaces 23 west of downtown. (The original routes seem counterintuitive, which is why an earlier edition of this map had to be corrected after looking at the DOT's archives.) 1929: US 77 extended north from South Sioux City, replacing westernmost piece of IA 141. Possibly concurrently, the segment from downtown to near South Dakota was realigned from Military Rd to Riverside Blvd and W. 4th St. Also in 1929: IA 12/29 realigned off Nebraska Street January 8, 1931: IA 230 designated February 7, 1931: IA 12/29 shifted onto 9th and Omaha streets between Geneva and 8th (this is the "notch" in the below maps) Between 1930 and June 1, 1932: US 75 realigned onto Plymouth St

Jct. 20/75: 4th/Plymouth to Correctionville/Fairmount Jct. 20/77: 4th (WB)/5th (EB)/Perry - also end of IA 12/29 End 141: Morningside at Lakeport NOTE: Highway Commission files indicate that 20/75 was broken up into one-ways, with eastbound using 1st Street (just north of Correctionville) and westbound using 2nd, west of Fairmount Street. 1932: US 73 extended north to South Sioux City 1933: US 77 realigned south of Dakota City; US 20 realigned west of South Sioux City July 23, 1934: US 75 rerouted south of 20; old route becomes extension of 141 (northwest of Morningside/Lakeport) and new 230 August 1934: US 20 removed from 2nd between Fairmount and Westcott. During the mid-1930s, westbound 20 will intersect 75 (and IA 141 will end) on 1st St at Westcott St, which is now northeast of the Business 20/Business 75 interchange. Between 1934 and 1936: Correctionville Road straightened Between 1937 and 1940: US 20 moved from 4th/5th to Grand Ave ca. 1939: NE 110 commissioned 1942: IA 377 and 378 commissioned

US 20 downtown: Toll bridge, Elm St, 3rd St, Pearl St, Riverside Dr, Grand Ave (which becomes Correctionville Road) Jct. 20/75: Correctionville/Westcott (slightly east of present interchange; Westcott goes north to become Plymouth) Jct. 20/77: 3rd/Elm (approx. where Wesley Parkway ramps are now) End 141: Fairmount at Correctionville (20) or Westcott (75) End 230: Lakeport at Morningside Late 1940s?: IA 12/29 moves from 8th to 7th near downtown Late 1940s: IA 230 extended west to US 75 along Transit Ave December 8, 1949: Four-lane US 75 extended south from Hinton to somewhere in northeastern Sioux City ("Another Stretch of Super-Highway Opened Thursday," Le Mars Globe-Post, Dec. 13) February 8, 1951: Tolls on Combination Bridge lifted 1954: US 77 built on new Gordon Drive/Riverside Blvd alignment west of bridge November 24, 1954: US 20 shifted onto new Gordon Drive alignment east of bridge ("New Highway 20 Is Now Open," Kingsley News-Times, Nov. 25); IA 141 moved onto it 1955: IA 141 restored to earlier alignment

Jct. 20/75: Gordon/Plymouth Jct. 20/77: Gordon may have run under north end of bridge. Connecting road in NE corner of area seems to be used. End 141: Gordon at Plymouth End 230: Transit at Fowler October 10, 1957: New paving puts IA 12 on Sioux River Rd and Riverside Blvd, ending duplexed with 77 at junction with 20 November 1957: IA 29 renumbered IA 7 ("Highway 29 Is No More; Is Highway 7," Le Mars Globe-Post, Dec. 9) December 19, 1957: Four-lane built between Prospect Street and Gordon Drive Viaduct as part of US 77 and US 20, including interchange with bridge. This was the first contracted segment of the interstate system in Iowa. October 1, 1958: Stretch of I-29 between Riverside Blvd and future Gordon Drive exit (including part of earlier-built piece) opens; IA 12 truncated to Riverside interchange November 28, 1959: I-29 opens south of present-day Singing Hills Blvd July 15, 1960: I-29 opens from US 77 to Singing Hills 1961: IA 141 removed from Sioux City area to meet I-29 at Sloan December 15, 1961: New I-29 bridge into North Sioux City SD opens; 77 put on 29 across river ("Dedicate Interstate Linking Iowa, South Dakota," Sioux City Journal, Dec. 15) November 16, 1964: Four-lane US 20 east to Moville opens 1965: IA 230 decommissioned 1968: US 75 put on I-29 from southern Sioux City to Council Bluffs; old road named IA 475 January 1, 1969: IA 7 decommissioned 1968-early 1970s: Interchange built between US 20 and US 75; 75's alignment near 20 changes slightly; all of US 75 becomes Lewis Blvd

NOTE: The Sioux City insets of all Iowa maps in the 1970s (but not the main maps) indicate US 73 remained in South Sioux City until the present alignments of US 20 and 77 were in place. Dale Sanderson and Jesse Whidden's sites say 73 was pulled back to Winnebago NE in 1965, where 73 leaves the duplex with 77. Rand McNally dropped the duplex by 1973. So the 73 on the above map may or may not be right. Jct. 20/75: Interchange, Gordon Dr/Lewis Blvd Jct. 20/77: Cloverleaf interchange with I-29 1972 or 1973: US 20 realigned around downtown South Sioux City (between 9th and 29th streets) 1974: IA 378 decommissioned 1975: IA 475 renumbered to IA 970 November 22, 1976: All of I-129 opens, as does new US 20 ("Freeway 520") east to Lakeport Ave 1977: US 20 taken off diagonal west of South Sioux City, now meets I-129 at 129's west end May 15, 1979: West ramps of I-29/US 77 interchange closed to begin construction on present bridge and volleyball interchange June 29, 1979: US 20 freeway completed, adding 20 to I-129; IA 12 extended along I-29 and Gordon Drive; old 20 in Sioux City and South Sioux City becomes Business 20; US 77 bypass of South Sioux City and Dakota City finished; NE 35 extended along old 77 November 22, 1979: US 75 becomes four lanes throughout Sioux City 1980: US 77 put on I-29 in North Sioux City, replaced by SD 105; IA 377 decommissioned, except for small piece west of I-29 January 15, 1981: New Veterans Memorial Bridge (US 77/Business 20) replaces Combination Bridge; open to four lanes on July 22 May 6, 1982: Combination bridge closes due to structural issues; reopens to two lanes on December 9 and four in May 1983 Also in 1982: US 77 truncated to I-29 interchange 1984: US 75 moved into Nebraska, replacing US 73 north of Omaha and creating "wrong-way" multiplex with I-29 between I-129 and Singing Hills 1988: IA 982 and other "no-name" 900 series highways signed July 19, 1989: United Airlines Flight 232 crashes at Sioux City Gateway Airport (which IA 377 and 378 used to serve).

1994: IA 970 turned over in Sergeant Bluff 1996: Rest of IA 970 turned over except one little piece 1998: SD 105 allegedly decommissioned in North Sioux City. Official county map shows 105 is only near Elk Point (off this map), but 2000 state map and I-29 exit sign (June 2005) still indicate 105 in area. 2000: IA 12 signage removed along I-29 and Business 20 2000?: NE 35 decommissioned in Dakota City to end at US 75/77 November 19, 2001: US 75 freeway opens on east side, removing multiplex with I-29 and adding multiplex with US 20; old 75 becomes secret IA 376 and Business 75

Early 2000s: Business 20 signage at east I-29 split removed; signs at US 77 interchange remain July 1, 2003: IA 982, remainder of IA 970, and remainder of IA 377 decommissioned

Maps on this page © Jeff Morrison 2005-06

Page created 9/10/05; last updated 5/18/08