Length in Iowa: 232 miles/373 kilometers
Northern terminus: Minnesota state line south of Jackson, MN
Southern terminus: Missouri state line at Braddyville
Counties: Dickinson, Clay, Buena Vista, Sac, Carroll, Audubon, Cass, Montgomery, Page
Cities along route: Spirit Lake, Okoboji, Arnolds Park, Milford,
Fostoria, Spencer, Sioux Rapids, Storm Lake, Early, Auburn,
Carroll, Audubon, Exira, Brayton, Atlantic, Grant, Villisca, Clarinda,
NHS: Entire route
Freeway segments: None
About 12 miles between Milford and Spencer
The 10 miles it shares with US 20 in Sac County
7 miles with IA 9 east of Spirit Lake
4 miles with US 18 through Spencer
5 miles with IA 10 in southern Clay and northern
Buena Vista counties through Sioux Rapids
2 miles with IA 7 southeast of Storm Lake
10 miles with US 20 between Exit #71 near Early and Exit #82 northeast of Sac City
8 miles with IA 175 in Sac County, west and north of Auburn
3 miles with IA 141 in southern Carroll County near
8½ miles with US 6 between I-80 and Atlantic; this
includes a two-mile triplex with IA 83 east of Atlantic.
2 miles with IA 92 north of Lyman
2 miles with IA 2 east of Clarinda
Designated: October 16, 1926, to sections of IA
4 (I) (between the Minnesota line and Early), IA
23 (I) (between Early and Sac City), and IA 18
(from Sac City to the Missouri line)
Paving history: At the time of designation, the segment from Milford to the Dickinson/Clay county line was paved.
1928: Paved from US 34 to Villisca
1929: Paved from the Carroll/Audubon county line to Audubon and from Clarinda to the Missouri state line
1930: Paved from Orleans to Milford, from the Dickinson/Clay county line to US 18 north of Spencer, from Audubon to the Audubon/Cass county line, from the Cass/Montgomery county line to US 34, and from Villisca to Clarinda
1931: Paved from a point south of Spencer to the Clay/Buena Vista county line, through Carroll County, and through Cass County. (The paving in Carroll County included an alignment shift east of Templeton that created IA 236; the old alignment followed present-day County Road E57.)
1932: Paved through Spencer and from Storm Lake to Early
1935: Paved from Storm Lake to a point south of Truesdale
1937: Paved from the Clay/Buena Vista county line to a point near Truesdale (on a new alignment, eventually creating IA 351 to serve Rembrandt and IA 352 to serve Truesdale) and from Early to Lake View
1938: Last segment, from Lake View to the Sac/Carroll county line, paved
Major alignment changes:
1934: Realigned between Spirit Lake and the Minnesota state line. This extended a multiplex with IA 9 and created IA 276 to serve Orleans.
March 26, 1935: Realigned in Sac County; it previously ran into Sac City and followed US 20 for an additional 10 miles west of it. (IA 196 was created as a result but the old route followed present-day County Road M54.)
September 18, 1973: Two-lane bypass to the south of Clarinda opened (with IA 2)
November 19, 1996: Bypass to the east of Storm Lake, which straightened US 71 in
Buena Vista County, completed.
June 14, 2016: Rerouted along US 20 and the former IA 196 between Early and a point east of Lake View, with IA 471 replacing the standalone segment between Early and IA 175. It previously shared an additional 10 miles with IA 175 on an east-west segment through Lake View.
November 23, 1992: Expressway segment between Milford and Spencer completed
May 2000: Expanded to four and five lanes between Milford and Spirit Lake, a plan that
was met with significant local opposition since it was first proposed in 1968 but completed one year ahead of schedule.
A new bypass to the west of Spencer, carrying US 18 and 71, was scheduled
to be completed in the fall of 2005 but pulled from the five-year plan in late 2001
due to budget problems. (The city of Spencer completed a "West Beltway" in 2013 but neither US 18 nor US 71 have been rerouted.) The rest of the route will gradually become a "Super-2" highway, but plans to improve segments between Carroll and Storm Lake and between Audubon and Atlantic were put on hold in September 2001.
Business US 71
Storm Lake: This route follows the old 12½-mile alignment of US 71
(which was left behind when the bypass to the east of town opened but not signed until December 1996): County Roads C43 and M44, Lake Avenue (which was unsigned IA 914 until October 26, 2001), and IA 7. (Terminus
Clarinda: This one follows the pre-1973 alignment of US 71, along Washington Street and Glenn Miller Avenue. AASHTO approved the designation on October 4, 1996. (Terminus