Plymouth County, IA

407 public highway bridges

Plymouth County Bridge Snapshot

Plymouth County, Iowa contains 407 public highway bridges in the FHWA National Bridge Inventory. Roughly 51.8% are rated “Good,” 24.6% “Fair,” 22.1% “Poor,” and 22.1% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in IA are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

407

Total Bridges

51.8%

Good

22.1%

Poor

22.1%

Structurally Deficient

Condition Distribution

Good

51.8% (211)

Fair

24.6% (100)

Poor

22.1% (90)

SD

22.1% (90)

All Bridges (407)

Sort:

200TH STREET

Over: IA 75

1.0 mi. N of jct. SR C38, Plymouth, IA

Built 2006 ADT: 7,300

IOWA 3

Over: US 75 (LEMARS BYPASS)

At the Jct. U.S. 75, Plymouth, IA

Built 2005 ADT: 5,800

US 75 NB

Over: IA 60

At jct. IA 60, Plymouth, IA

Built 2005 ADT: 2,085

US 75 SB

Over: IA 60

At jct. Iowa 60, Plymouth, IA

Built 2005 ADT: 2,085

US 75 NB

Over: LAKE AVENUE

1.1 mi S of jct IA 60, Plymouth, IA

Built 2006 ADT: 50

US 75 SB

Over: LAKE AVENUE

1.1 mi S of jct IA 60, Plymouth, IA

Built 2006 ADT: 50

NB US 75

Over: DRY CREEK

2.3 mi N of SR C60, Plymouth, IA

Built 1972 ADT: 7,000

NB US 75

Over: DRY CREEK

3.4 mi. N of jct. SR C60, Plymouth, IA

Built 1972 ADT: 7,000

NB US 75

Over: DRY CREEK

1.5 mi. S of SR C44, Plymouth, IA

Built 1972 ADT: 7,000

NATURE AVE

Over: PLYMOUTH CREEK

092452502, Plymouth, IA

Built 1940 Load: 13.5 t ADT: 45

NB US 75

Over: FLAT CREEK

1.2 mi. S of SR C44, Plymouth, IA

Built 1972 Load: 13.8 t ADT: 7,000

180TH ST

Over: WESTFIELD CREEK

092481701, Plymouth, IA

Built 1900 Load: 14.0 t ADT: 11

JADE AVE

Over: DRAINAGE

090460304, Plymouth, IA

Built 1989 Load: 14.4 t ADT: 50

300TH ST

Over: DEER CREEK

090431701, Plymouth, IA

Built 1990 Load: 15.1 t ADT: 30

200TH ST

Over: BROKEN KETTLE CREEK

092482501, Plymouth, IA

Built 1972 Load: 15.2 t ADT: 20

250TH ST

Over: DRAINAGE

091472103, Plymouth, IA

Built 1978 Load: 15.5 t ADT: 15

190TH ST

Over: WESTFIELD CREEK

092492404, Plymouth, IA

Built 1962 Load: 15.5 t ADT: 15

150TH ST

Over: W BR FLOYD RIVER

093453101, Plymouth, IA

Built 1963 Load: 15.5 t ADT: 50

110TH ST

Over: FLOYD RIVER

093440703, Plymouth, IA

Built 1940 Load: 16.3 t ADT: 60

FIR AVE

Over: BULL RUN

092472802, Plymouth, IA

Built 1949 Load: 16.8 t ADT: 26

FM K-18

Over: BROKEN KETTLE CREEK

091482706, Plymouth, IA

Built 1979 Load: 17.0 t ADT: 490

FM

Over: MINK CREEK

093462202, Plymouth, IA

Built 1961 Load: 17.0 t ADT: 559

IA 12

Over: DRAINAGE DITCH

1.5 mi S of S jct SR K18, Plymouth, IA

Built 1957 Load: 17.1 t ADT: 1,840

IA 12

Over: DRAINAGE DITCH

2.0 mi. S of S jct SR K18, Plymouth, IA

Built 1957 Load: 17.2 t ADT: 1,840

LOCAL

Over: DEEP CREEK

092430604, Plymouth, IA

Built 1953 Load: 17.5 t ADT: 609

160TH ST

Over: BROKEN KETTLE CREEK

092470401, Plymouth, IA

Built 1964 Load: 17.6 t ADT: 20

FM

Over: MINK CREEK

093462702, Plymouth, IA

Built 1961 Load: 17.6 t ADT: 628

DOGWOOD AVE

Over: INDIAN CREEK

093481102, Plymouth, IA

Built 1984 Load: 17.7 t ADT: 11

NB US 75

Over: STREAM

1.3 mi N of SR C60, Plymouth, IA

Built 1950 Load: 18.1 t ADT: 7,000

IA 140

Over: DRAINAGE

1.4 S of S.R. C38, Plymouth, IA

Built 1963 Load: 18.1 t ADT: 970

SB US 75

Over: DRAINAGE DITCH

3.0 mi. N of SR C60, Plymouth, IA

Built 1948 Load: 18.9 t ADT: 7,000

FM C-44

Over: SMALL

091452301, Plymouth, IA

Built 1978 Load: 19.0 t ADT: 190

FM K-42

Over: MINK CREEK

092460304, Plymouth, IA

Built 1961 Load: 19.0 t ADT: 628

FM

Over: MINK CREEK

093463402, Plymouth, IA

Built 1961 Load: 19.0 t ADT: 628

NB US 75

Over: DRAINAGE DITCH

2.6 mi. S of SR C44, Plymouth, IA

Built 1972 Load: 20.1 t ADT: 7,000

NATURE AVE

Over: PLYMOUTH CREEK

092453602, Plymouth, IA

Built 1900 Load: 21.0 t ADT: 100

FM C-70

Over: WEST FORK LITTLE SIOUX

090443503, Plymouth, IA

Built 1961 Load: 21.1 t ADT: 459

FM

Over: BULL RUN CREEK

092483601, Plymouth, IA

Built 1960 Load: 21.2 t ADT: 838

FM C-16

Over: DEEP CREEK

093432101, Plymouth, IA

Built 1960 Load: 21.4 t ADT: 409

FM

Over: MINK CREEK

093461502, Plymouth, IA

Built 1961 Load: 21.5 t ADT: 559

NB US 75

Over: DRAINAGE DITCH

3.0 mi. N of Jct. SR C60, Plymouth, IA

Built 1972 Load: 21.6 t ADT: 7,000

240TH ST

Over: DRY BRANCH

091441601, Plymouth, IA

Built 1900 Load: 22.0 t ADT: 71

LOCAL

Over: CLEAR CREEK

092433002, Plymouth, IA

Built 1959 Load: 22.3 t ADT: 399

280TH ST

Over: DEER CREEK

090430501, Plymouth, IA

Built 1956 Load: 22.5 t ADT: 11

JUNIPER AVE

Over: DRAINAGE

092461402, Plymouth, IA

Built 1900 Load: 22.5 t ADT: 20

FM C-44

Over: BROKEN KETTLE CREEK

091481105, Plymouth, IA

Built 1965 Load: 22.6 t ADT: 120

FM

Over: W BR FLOYD RIVER

093453001, Plymouth, IA

Built 1968 Load: 22.6 t ADT: 270

SUNSET AVE

Over: DD

091430202, Plymouth, IA

Built 1950 Load: 22.8 t ADT: 30

150TH ST

Over: MINK CREEK

093463301, Plymouth, IA

Built 1961 Load: 22.8 t ADT: 26

US 75

Over: STREAM

0.1 mi S of Jct. SR C80, Plymouth, IA

Built 1999 Load: 23.0 t ADT: 18,200

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 6, 2026