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. Each box lists all the changes that happened between the above and below maps. Four-lane roads are shown as thicker lines, although in this case they are more like urban arterials than freeways/expressways. 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, Plymouth St, Westcott St, 2nd St/Fairmount St (EB) and 1st St (WB), then south to intersection of Fairmount/Correctionville
IA 12, N-S: Broken Kettle Rd, Stone Park Blvd, 27th St (1 block), Nebraska St, 5th St, Court St (1 block), triplex route above, Fairmount St (2 blocks), Leech Ave (2 blocks), Rustin St (4 blocks), Jay Ave (3 blocks), Morningside Ave, Smithland Rd

End IA 5: Probably Court at 4th. IA 29 may or may not have been duplexed a block with it. No connection to NE 5.
End 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 South 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 Road to Riverside Boulevard and West 4th Street.
Also in 1929: IA 12/29 moved off Nebraska Street onto (N-S) 32nd Street, Hamilton Street, 24th Street, Geneva Street, West 14th Street, Otoe Street, W 8th Street, Perry Street, Wesley Way, and 5th 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)
July 8, 1931: US 75 realigned onto Plymouth Street
1931: Correctionville Road straightened in eastern Sioux City; old segment now Green Avenue (segment between Logan and Martha streets removed in 1980s for construction of Hy-Vee)
1932: US 73 extended north to South Sioux City

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 (1st at Westcott 1934-36, Fairmount at Correctionville 1936-39, Linn at Correctionville after that)

NOTE: Highway Commission files and monthly maps disagree on the routing of US 20 in 1932. Minutes indicate that 20 eastbound used 1st Street (just north of Correctionville) and westbound used 2nd Street between Westcott and Fairmount until 1934. This is what's shown above. Inset maps from 1932 show 2nd only, and then one-ways farther west: Court/5th (WB) and Nebraska/4th (EB). I have marked this as a thinner line. If this happened, it occurred in 1931 or early 1932. (Then the insets disappear and the Grand Avenue viaduct is built so the whole thing becomes moot.)

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 onto Westcott Street, Dace Avenue, Fowler Street, Williams Avenue, and Lewis Road (eventually renamed Lewis Boulevard); previous Lakeport Road alignment becomes new IA 230; IA 141 extended along 75's old route (Morningside, Jay, Rustin, Leech, Fairmount, 1st) to US 20
August 15, 1934: US 20 (westbound only?) removed from 2nd between Fairmount and Westcott
February 5, 1936: IA 141 truncated to US 20 (loses three blocks on Fairmount and 1st)
October 1937: Grand Avenue viaduct completed - but connections missing
June 21, 1939: US 20 rerouted onto path to use Grand Avenue viaduct, a year after previously planned; IA 141's end at US 20 moved one block west (Fairmount-Dace-Linn)
1939: NE 110 commissioned
ca. 1942: IA 377 and 378 commissioned

US 20 downtown: Toll bridge, 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: Linn at Correctionville, or possibly one block west at Westcott
End 230: Lakeport at Morningside

NOTE: A 1939 construction plan shows work on Transit Avenue between US 75 and Rustin Street, but I can't find any other evidence that Transit between 75 and Morningside was a state highway prior to 1948.

NOTE: Exact date of realignment of US 77 off much of Military Road in North Sioux City (to the other side of railroad tracks with double underpass) unknown. Aerial photos indicate road existed as early as late 1930s.

1940s: IA 141 moved from Jay Avenue and Rustin Street to Cecilia Avenue and Dodge Avenue between the Morningside/Cecilia and Dodge/Rustin intersections
1948: IA 230 extended from IA 141 west along new/rebuilt Transit Avenue to US 75 at Vine Avenue
1948: Grand Avenue Viaduct renamed Gordon Drive Viaduct
1949: US 77 moved onto new Gordon Drive paralleling Missouri River
December 8, 1949: Four-lane US 75 extended south from Hinton to northeastern corner of Sioux City ("Another Stretch of Super-Highway Opened Thursday," Le Mars Globe-Post, Dec. 13)
February 8, 1951: Tolls on Combination Bridge lifted

Jct. 20/75: Gordon/Westcott. US 20 transitions to/from Correctionville Road via now-vanished short diagonal east of Linn Street.
Jct. 20/77: Connector of 3rd and Pearl because new Gordon Drive goes under bridge
IA 141 (E-W): Smithland Road, Morningside Avenue, Cecilia Street, Dodge Avenue, Rustin Street, Leech Avenue, Fairmount Street, Dace Avenue, Linn Street (end at Gordon)

NOTE: It is possible that IA 141 was routed onto Transit and Fowler instead of Palmetto and Gordon from sometime in 1955 to sometime in 1956. It is possible that IA 230 was duplexed with Fowler up to US 20 in 1955 or 1956 until 1957. Or they both could be inset map errors.

NOTE: Sioux City inset maps from 1952-55 show the northernmost part of IA 12 on Memorial Drive and Talbot Street (west of Stone Park Boulevard) but there has never been a road running north from Talbot to present-day K18. The main map was not affected. I believe this to be a map error until proven otherwise.

1954: IA 12/29 moves from 8th Street to 7th Street near downtown
November 24, 1954: US 20 shifted onto new Gordon Drive alignment east of Combination Bridge ("New Highway 20 Is Now Open," Kingsley News-Times, Nov. 25); IA 141 moved onto it
1955: IA 29 reconstructed from Perry Creek northward to city limits, eliminating very early 16-foot-wide concrete paving, clipping some old curves, and eliminating Summit Street/38th Street portion
1956: IA 141 returned to old route between Morningside Avenue and US 20, except using all Fairmount instead of Fairmount-Dace-Linn between Leech Avenue and 20
1957: IA 378 extended east to IA 230
1957: Iowa swing span (northernmost part) of Combination Bridge removed; US 77 bridge over future I-29 built in same position
June 25, 1957: US 75 opens to four lanes undivided from 14th Street to 41st Street and then four lanes divided, with interchange At 46th Street/Floyd Boulevard, up to Plymouth County line ("Highway 75 To Open Tomorrow," Le Mars Globe-Post, June 24)
October 10, 1957: IA 12 put on newly paved Sioux River Road, which runs into Riverside Boulevard, along the Big Sioux River, ending duplexed with US 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 15, 1957: Combination Bridge interchange and four-lane road opens from the intersection of Pearl Street and Gordon Drive west to Isabella Street (now Hamilton Boulevard). This was the first contracted segment of the interstate system in Iowa.
1958: IA 7/new Hamilton Boulevard straightened between 7th Street and Dearborn Boulevard
October 1, 1958: Stretch of I-29 between Riverside Boulevard and future Gordon Drive exit (including earlier-built piece) opens; IA 12 truncated to Riverside interchange
November 28, 1959: I-29 opens south of present-day Singing Hills Boulevard, then named Industrial Road
July 15, 1960: I-29 opens from US 77 to Singing Hills; US 20 (Gordon Drive) reworked/expanded between Pearl Street and Floyd Boulevard
1960: Westcott Street (US 75) bridge over old Floyd River channel rebuilt (this bridge still exists today, but over dry land, visible in the southeast quadrant of the intersection of Lewis Boulevard and 3rd Street)
1961: IA 141 removed from Sioux City area to meet I-29 at Sloan (probably Oct. 26, when I-29 opened between Sloan and Onawa)
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)

Jct. 20/75: Gordon/Westcott. US 20 transitions to/from Correctionville Road via now-vanished short diagonal east of Linn Street.
Jct. 20/77: Combination Bridge interchange with I-29

April 1, 1962: Northbound I-29 bridge over Big Sioux River collapses after heavy spring floods
February 1-September 13, 1963: Gordon Drive viaduct closed, partially demolished, rebuilt for rechanneling of Floyd River
1963: Replacement northbound I-29 bridge over Big Sioux River opens
November 16, 1964: Four-lane US 20 east to Moville opens
1965: IA 230 decommissioned; IA 378 truncated to US 75
November 1966: Gordon Drive Viaduct expanded to four lanes
1968: US 20/75 interchange (Gordon Drive and Lewis Boulevard) opens
June 18, 1968: AASHTO denies reroute of US 75 over Gordon Drive and Combination Bridge
October 25, 1968: US 75 put on I-29 from southern Sioux City (Industrial Road exit) to Council Bluffs; old road named IA 475 but not signed
January 1, 1969: IA 7 decommissioned
1969: Gordon Drive expanded to four lanes
1971 or early 1972: US 20 realigned around downtown South Sioux City (between 9th and 29th streets)
Dec. 3, 1971: US 73 truncated from South Sioux City to Winnebago (approved by AASHTO), eliminating it from the area. However, some maps had it gone as early as the mid-1960s. It remained in place on the Sioux City inset of the Iowa state map throughout the 1970s, finally disappearing in 1979.

Jct. 20/75: Interchange, Gordon Drive/Lewis Boulevard
Jct. 20/77: Cloverleaf interchange with I-29

1972: I-29 Isabella Street exit renamed Hamilton Boulevard after extension of city street
ca. 1973: US 75 and railroad tracks "bent" in slight curve to accommodate I-129 interchange
1974: IA 378 decommissioned
1975: IA 475 renumbered IA 970
November 22, 1976: All of I-129 opens, as does new US 20 ("Freeway 520") east to Lakeport Avenue
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 (old bridge came up to SE corner of volleyball)
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 on south side of Sioux City, including realignment in Floyd Park area and true interchange with Transit Street
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
October 3, 1981: US 77 truncated to I-29 volleyball interchange, making signs erected mere months before obsolete (however, the 1983 state map still had 77 markers in SD)
May 6, 1982: Veterans Memorial Bridge closes due to structural issues; reopens to two lanes on December 9 and four in May 1983
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 Boulevard
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 in June 2005 still indicated 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 Business 75 and secret IA 376

Early 2000s: Business 20 signage at east I-29 split removed; signs at US 77 interchange remain
March 28, 2002: Sioux City Stockyards close, leaving some signs on I-29 blank for years
July 1, 2003: IA 982, remainder of IA 970, and remainder of IA 377 decommissioned
2006 or 2007: US 20 four-laned from previous end west to Jackson NE
2010: Decade-long project to modernize and expand I-29 to six lanes throughout Sioux City begins
2012: IA 12 interchange converted from trumpet to diamond

Some information used from "Sioux City's Grand Avenue Viaduct 1936-2010" on the Iowa DOT's website.

Maps on this page © Jeff Morrison 2005, 2015

Page created 9/10/05; updated 10/14/12; revised and expanded 1/25/15

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