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:

GRANITE AVE

Over: PERRY CREEK

091472202, Plymouth, IA

Built 1952 Load: 15.6 t ADT: 5

260TH ST

Over: DRY BRANCH

091442801, Plymouth, IA

Built 1956 Load: 15.8 t ADT: 34

160TH ST

Over: DEEP CREEK

092440201, Plymouth, IA

Built 1900 Load: 16.2 t ADT: 71

GRANITE AVE

Over: BROKEN KETTLE CREEK

093472202, Plymouth, IA

Built 1959 Load: 16.3 t ADT: 20

240TH ST

Over: BIG WHISKEY SLOUGH

091431401, Plymouth, IA

Built 1953 Load: 16.7 t ADT: 11

LOCAL

Over: DRAINAGE

090461903, Plymouth, IA

Built 1955 Load: 16.8 t ADT: 30

IMPALA AVE

Over: MINK CREEK

092460502, Plymouth, IA

Built 1938 Load: 16.8 t ADT: 26

FIR AVE

Over: BULL RUN

092473302, Plymouth, IA

Built 1948 Load: 16.8 t ADT: 30

180TH ST

Over: WESTFIELD CREEK

092481501, Plymouth, IA

Built 1948 Load: 16.8 t ADT: 20

SHAMROCK AVE

Over: DEEP CREEK

093431502, Plymouth, IA

Built 1953 Load: 17.1 t ADT: 50

230TH ST

Over: RATHBURN CREEK

091430801, Plymouth, IA

Built 1900 Load: 17.2 t ADT: 30

270TH ST

Over: CARTER CREEK

091463503, Plymouth, IA

Built 1900 Load: 17.2 t ADT: 11

OTTER AVE

Over: WILLOW CREEK

093442902, Plymouth, IA

Built 1949 Load: 17.2 t ADT: 15

190TH ST

Over: MINK CREEK

092462201, Plymouth, IA

Built 1947 Load: 17.3 t ADT: 15

QUEST AVE

Over: RATHBURN CREEK

091431902, Plymouth, IA

Built 1950 Load: 17.8 t ADT: 26

MARBLE AVE.

Over: PLYMOUTH CREEK

092453502, Plymouth, IA

Built 1946 Load: 18.0 t ADT: 5

FAWN AVE

Over: BROKEN KETTLE CREEK

091470804, Plymouth, IA

Built 1953 Load: 18.1 t ADT: 11

150TH ST

Over: FLOYD RIVER

093453403, Plymouth, IA

Built 1954 Load: 18.4 t ADT: 131

IRIS AVE

Over: MINK CREEK

093462102, Plymouth, IA

Built 1900 Load: 18.6 t ADT: 34

FM C-43

Over: BROKEN KETTLE CREEK

091482205, Plymouth, IA

Built 1960 Load: 19.0 t ADT: 159

LYNX AVE

Over: MUDDY CREEK

090453302, Plymouth, IA

Built 1949 Load: 20.0 t ADT: 34

EVERGREEN AVE

Over: INDIAN CREEK

093471902, Plymouth, IA

Built 1900 Load: 20.2 t ADT: 20

LOCAL

Over: WILLOW CREEK

093430701, Plymouth, IA

Built 1941 Load: 20.6 t ADT: 60

200TH ST

Over: MINK CREEK

092462701, Plymouth, IA

Built 1949 Load: 20.9 t ADT: 34

JUNIPER AVE

Over: MINK CREEK

093460202, Plymouth, IA

Built 1948 Load: 20.9 t ADT: 34

120TH ST

Over: INDIAN CREEK

093481401, Plymouth, IA

Built 1900 Load: 21.2 t ADT: 20

JUNIPER AVE

Over: MINK CREEK

093461102, Plymouth, IA

Built 1900 Load: 21.4 t ADT: 45

190TH ST

Over: DRAINAGE

092462301, Plymouth, IA

Built 1949 Load: 21.5 t ADT: 20

200TH ST

Over: CLEAR CREEK

092433003, Plymouth, IA

Built 1946 Load: 21.7 t ADT: 5

SUNSET AVE

Over: DD

091431402, Plymouth, IA

Built 1956 Load: 22.0 t ADT: 20

240TH ST

Over: PERRY CREEK

091471401, Plymouth, IA

Built 1900 Load: 22.1 t ADT: 5

330TH ST

Over: CREEK

090433103, Plymouth, IA

Built 1956 Load: 23.2 t ADT: 60

140TH ST

Over: BROKEN KETTLE CREEK

093472801, Plymouth, IA

Built 1948 Load: 23.3 t ADT: 20

DIAMOND AVE

Over: WESTFIELD CREEK

092480302, Plymouth, IA

Built 1900 Load: 23.6 t ADT: 11

RITCHIE RD

Over: MUD CREEK

091443103, Plymouth, IA

Built 1948 Load: 23.9 t ADT: 15

ROOSEVELT AVE

Over: DD

091432802, Plymouth, IA

Built 1900 Load: 24.0 t ADT: 15

DIAMOND AVE

Over: BEAVER CREEK

093482702, Plymouth, IA

Built 1900 Load: 24.0 t ADT: 26

280TH ST

Over: PERRY CREEK

090470401, Plymouth, IA

Built 1900 Load: 24.1 t ADT: 20

300TH ST

Over: MUD CREEK

090451301, Plymouth, IA

Built 1950 Load: 24.3 t ADT: 50

190TH ST

Over: BULL RUN

092472101, Plymouth, IA

Built 1961 Load: 24.3 t ADT: 50

POLK AVE

Over: DEEP CREEK

092440202, Plymouth, IA

Built 1958 Load: 24.5 t ADT: 60

FM K-42

Over: CARTER CREEK

090460202, Plymouth, IA

Built 1966 Load: 25.0 t ADT: 190

190TH ST

Over: WESTFIELD CREEK

092481901, Plymouth, IA

Built 1951 Load: 26.8 t ADT: 26

150TH ST

Over: BROKEN KETTLE CREEK

093473501, Plymouth, IA

Built 1952 Load: 29.4 t ADT: 11

150TH ST

Over: BROKEN KETTLE CREEK

093473601, Plymouth, IA

Built 1952 Load: 35.0 t ADT: 26

FM

Over: STEPHENS CREEK

090481506, Plymouth, IA

Built 1960 Load: 44.3 t ADT: 628

165TH ST

Structurally Deficient

Over: WEST BRANCH FLOYD RIVER

092450603, Plymouth, IA

Built 1911 Load: 4.5 t ADT: 120

120TH ST

Structurally Deficient

Over: W BR FLOYD RIVER

093451803, Plymouth, IA

Built 1941 Load: 6.2 t ADT: 20

GRANITE AVE

Structurally Deficient

Over: BROKEN KETTLE CREEK

093473402, Plymouth, IA

Built 1900 Load: 7.0 t ADT: 34

BLUEBIRD AVE

Structurally Deficient

Over: DRAINAGE

092483102, Plymouth, IA

Built 1949 Load: 7.7 t ADT: 20

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