Length in Iowa: 108 miles/174 kilometers
Northern terminus: Wisconsin state line (Mississippi River) at Dubuque with US 61
Southern terminus: I-80 (exit #225) south of the Amana Colonies
Counties: Dubuque, Jones, Linn, Benton, Iowa
Cities along route: Dubuque, Cascade, Monticello, Anamosa, Springville,
Marion, Bertram, Cedar Rapids, Fairfax, Walford
NHS: From Wisconsin state line to US 30 near Cedar Rapids (including
the duplex with US 30)
2 miles, from the Wisconsin state line to US 52/IA 3 in Dubuque (with US 61)
6 miles, with US 30 and US 218 southwest of Cedar Rapids
6 miles, from US 52/IA 3 in Dubuque to the interchange with US 61 near the Dubuque Regional Airport
65 miles, between the split with US 30 (southeast of Cedar Rapids) and the split with US 61 (near the Dubuque Regional Airport); this includes two interchanges apiece near Cascade, Monticello, and Anamosa
The 5 miles it shares with US 30, from the end of the freeway segment in Cedar Rapids (east of I-380) to just east of the Cedar River crossing.
Expressway segment through Dubuque
Expressway segment between Dubuque and Cedar Rapids
Freeway bypass of Cedar Rapids
8 miles with US 61, from the Wisconsin state line through
Dubuque to the interchange north of the Dubuque Airport; this includes a 3½-mile triplex
with US 52 in Dubuque.
7½ miles with IA 13 between the outskirts of Marion
and US 30
10½ miles with US 30 (including a 4-mile triplex with
US 218), from the Williams Boulevard exit southwest of Cedar
Rapids to IA 13
2 miles with US 6 west of Homestead
Designated: January 1, 1938 (approved October 11, 1937), to the former US 161 north of Cedar Rapids. (Present-day US 151 in southwest Wisconsin was known as US 118 before then.)
Paving history: The entire road was paved at the time of designation.
Major alignment changes:
November 12, 1965: Two-lane bypass around Anamosa (with IA 64) opens; IA 64 was taken off US 151 when it was shortened to its current west end in 1969.
May 14, 1969: US 151 and 61 rerouted to follow US 20 across the Julien Dubuque Bridge into Illinois after new weight limits were placed on the Eagle Point Bridge. The two highways ran about 3 miles through East Dubuque before
entering Wisconsin. (The Eagle Point Bridge would remain open to traffic until late 1982.)
August 21, 1982: Dubuque-Wisconsin Bridge opens, restoring the direct US 61/151 route between Iowa and Wisconsin.
September 19, 1985: Extended from its southern terminus in downtown Cedar Rapids to its present end at I-80, taking part of IA 149's old route through the Amana Colonies and running along a new two-lane road south of US 6. (AASHTO approved the extension on April 21, 1996, more than a decade after the fact, after denying Iowa's request twice in 1986.)
July 7, 1989: Re-routed around Cedar Rapids and Marion by piggybacking with IA 13 to the east and US 30 and 218 to the south. (The old route through the two cities was designated as Business US 151.)
For alignment changes in Dubuque that are not listed here, see Jeff Morrison's Dubuque Highway Chronology page.
For other alignment changes in Cedar Rapids that are not listed here, see the Highways of Cedar Rapids page.
1957: Original segment of expressway in Dubuque, from Grandview Avenue to the split with US 61, opens
December 10, 1971: The interchange with US 61 south of Dubuque opens, as does a two-mile segment west of US 61 near the Dubuque Airport; US 151 was then relocated onto a four-lane segment of US 61 that existed since December 11, 1967. The old segment of US 151 was still maintained by the state as unsigned IA 963 until July 1, 2003.
January 28, 1991: 1½-mile expressway segment from Grandview Avenue to 4th Street in Dubuque opens (with US 52 and US 61)
December 26, 1991: 2-mile freeway segment from 11th Street to the Dubuque-Wisconsin Bridge opens to southbound traffic (with US 61); it would open to northbound traffic on August 25, 1992.
November 1992: 8-mile expressway segment, from the IA 13 split to Springville, opens
August 19, 1993: Last piece of the Dubuque freeway/expressway, the ½-mile segment from 4th Street to 11th Street, opens (with US 52 and US 61)
1995: 1-mile expressway segment in Marion, from the IA 13 split southward to future IA 100, opens
November 19, 1997: 3-mile expressway segment from IA 100 to Mount Vernon Road opens
May 2000: 3½-mile expressway segment between Mount Vernon Road and US 30 opens.
August 3, 2001: 4-mile expressway segment between Springville and a point west of IA 1 opens.
November 19, 2001: 6-mile expressway segment between IA 1 and Anamosa opens.
September 11, 2002: 5½-mile expressway bypass of Cascade opens.
October 14, 2003: 2-mile expressway segment from County Road E17 to a point south of County Road X44 (east of unincorporated Langworthy) opens. The old segment became the unsigned IA 337 (III).
May 2004: 4-mile expressway segment between Anamosa and County Road E17 opens
June 2004: 6-mile expressway segment between County Road D65 and Cascade opens
July 30, 2004: 5-mile bypass of Monticello opens; the old segment was briefly designated as the unsigned IA 303 (II) before it was transferred to local jurisdictions and is still signed as Business US 151.
September 13, 2004: 14-mile segment between Cascade and the Dubuque Airport opens, completing the four-lane
link between Cedar Rapids and Dubuque
US 151 and 218 run in opposite directions; therefore, while traveling
westbound on the four-mile stretch of US 30, you're also going southbound
on US 151 and northbound on US 218 (and vice versa when traveling
eastbound). By contrast, the triplex of US 52,
61, and 151 in Dubuque is all signed in one direction either way.
The 1985 extension to the Amana Colonies came after nearly two decades of
controversy over how to improve the gravel road (County Road L, later W21) that was
the most direct connection between I-80 and the Amanas when that segment of I-80 opened.
In 1968 the Highway Commission unveiled plans for a freeway, known as "Freeway 549," between
I-80 and Cedar Rapids. Many Amana residents felt that a freeway would disrupt the historic atmosphere
of the Colonies, not to mention the fact that another freeway — I-380 — was
under construction less than 20 miles to the east. The Highway Commission canceled
the freeway in a unanimous vote on October 12, 1971. The Transportation Commission,
which replaced the Highway Commission when the DOT was formed in 1974, voted to build
a two-lane road between I-80 and US 6 on December 1, 1975. The catch: it would make a
diagonal turn to meet US 6. In the wake of the I-35 and I-380 diagonal controversies,
a law (Section 306.9 of the Iowa
Code) was passed discouraging diagonal roads, and in 1980 the Iowa Supreme Court found that the
Commission's plans violated that law. After turning down a plan to pave the existing gravel road,
the Commission decided to build a straight connection to US 6 in 1984.
In December 1997, the Iowa DOT added US 151 between the Amana Colonies
and US 30 southwest of Cedar Rapids to its list of future "Super-2"
highways; plans to improve it were postponed in September 2001 as a result
of state funding shortages.
Business US 151
Cascade: Signed since mid-2004 along US 151's old route (1st Avenue) from the junction with US 151 to the interchange with County Road Y13. It was not originally signed from US 151 but is signed as of July 2005. Most of the markers for this business route were circles (as if it was Business IA 151) early on but the shields have since been replaced. AASHTO approved the designation on October 7, 2003, two years after the bypass opened. (Terminus photos)
Monticello: Designated in October 2004, after construction of the bypass was finished. It follows old US 151 (Main Street) and County Road X44. (Terminus photos)
Cedar Rapids and Marion: Designated in July 1989 after US 151 was re-routed along US 30 and IA 13. The 13-mile route follows Williams Boulevard and 1st Avenue in Cedar Rapids, and Marion Boulevard and 7th Avenue in Marion. (AASHTO did not approve the designation until April 27, 1997, nearly eight years after the fact.) The 9-mile segment through Cedar Rapids is designated (but not signed) as IA 922. (Terminus