Bridge conditions in Plymouth County, Iowa
430 inventoried bridges · 90 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Plymouth County has 90 bridges rated poor out of 430 inventoried, a 20.9% share that puts it well above the national rate of about 7%.
- 90 of the 430 bridges in Plymouth County, Iowa, are rated in poor condition (20.9%) in the 2025 National Bridge Inventory, as of .
- 233 bridges (54.2%) are rated good and 107 (24.9%) fair.
- The median Plymouth County bridge was built in 1978.
- The busiest poor-rated bridge is US 75 over Stream (built 1926), carrying about 14,000 vehicles a day.
Good 54.2% · Fair 24.9% · Poor 20.9% of 430 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 75 over Stream | 1926 | 14,000 | Poor |
| FM over Stephens Creek | 1960 | 628 | Poor |
| FM K-42 over Carter Creek | 1941 | 190 | Poor |
| FM K-42 over Carter Creek | 1966 | 190 | Poor |
| FM C-43 over Broken Kettle Creek | 1960 | 159 | Poor |
| 150TH St over Floyd River | 1954 | 131 | Poor |
| 165TH St over West Branch Floyd River | 1911 | 120 | Poor |
| Lone Tree Rd over Perry Creek | 1953 | 71 | Poor |
| 160TH St over Deep Creek | 1900 | 71 | Poor |
| 200TH St over W.branch Floyd River | 1960 | 71 | Poor |
| Tamarack Ave over Drainage Ditch | 1948 | 60 | Poor |
| 330TH St over Creek | 1956 | 60 | Poor |
| Polk Ave over Deep Creek | 1958 | 60 | Poor |
| Local over Willow Creek | 1941 | 60 | Poor |
| Quartz Ave over Willow Creek | 1946 | 60 | Poor |
| 140TH St over Floyd River | 1954 | 60 | Poor |
| Lynx Ave over Big Whiskey Creek | 1958 | 50 | Poor |
| 300TH St over Mud Creek | 1950 | 50 | Poor |
| 190TH St over Bull Run | 1961 | 50 | Poor |
| Shamrock Ave over Deep Creek | 1953 | 50 | Poor |
| Juniper Ave over Mink Creek | 1900 | 45 | Poor |
| Lynx Ave over Muddy Creek | 1949 | 34 | Poor |
| 260TH St over Dry Branch | 1956 | 34 | Poor |
| 170TH St over Drainage | 1900 | 34 | Poor |
| 200TH St over Mink Creek | 1949 | 34 | Poor |
| 200TH St over Mink Creek | 1953 | 34 | Poor |
| Juniper Ave over Mink Creek | 1948 | 34 | Poor |
| Iris Ave over Mink Creek | 1900 | 34 | Poor |
| Granite Ave over Broken Kettle Creek | 1900 | 34 | Poor |
| 310TH St over Creek | 1900 | 30 | Poor |
| 320TH St over Creek | 1900 | 30 | Poor |
| Local over Drainage | 1955 | 30 | Poor |
| 230TH St over Rathburn Creek | 1900 | 30 | Poor |
| Pioneer Ave over Deep Creek | 1917 | 30 | Poor |
| Fir Ave over Broken Kettle Creek | 1900 | 30 | Poor |
| Fawn Ave over Drainage | 1900 | 30 | Poor |
| Fir Ave over Bull Run | 1948 | 30 | Poor |
| 200TH St over Drainage | 1959 | 30 | Poor |
| 140TH St over Drainage | 1961 | 30 | Poor |
| Noble Ave over Deep Creek | 1953 | 30 | Poor |
| 280TH St over Mud Creek | 1900 | 26 | Poor |
| 300TH St over Johns Creek | 1900 | 26 | Poor |
| 310TH St over Dry Branch | 1941 | 26 | Poor |
| Quest Ave over Rathburn Creek | 1950 | 26 | Poor |
| Lynx Ave over Plymouth Creek | 1960 | 26 | Poor |
| 220TH St over Drainage | 1958 | 26 | Poor |
| Impala Ave over Mink Creek | 1938 | 26 | Poor |
| 190TH St over Westfield Creek | 1951 | 26 | Poor |
| 150TH St over Broken Kettle Creek | 1952 | 26 | Poor |
| Diamond Ave over Beaver Creek | 1900 | 26 | Poor |
| 280TH St over Perry Creek | 1900 | 20 | Poor |
| Sunset Ave over Dd | 1956 | 20 | Poor |
| 190TH St over Drainage | 1949 | 20 | Poor |
| 180TH St over Westfield Creek | 1948 | 20 | Poor |
| Bluebird Ave over Drainage | 1949 | 20 | Poor |
| 120TH St over W Br Floyd River | 1941 | 20 | Poor |
| 130TH St over W Br Floyd River | 1900 | 20 | Poor |
| 130TH St over Drainage | 1961 | 20 | Poor |
| Evergreen Ave over Indian Creek | 1900 | 20 | Poor |
| Granite Ave over Broken Kettle Creek | 1959 | 20 | Poor |
| 140TH St over Broken Kettle Creek | 1948 | 20 | Poor |
| 140TH St over Indian Creek | 1956 | 20 | Poor |
| 120TH St over Indian Creek | 1900 | 20 | Poor |
| Roosevelt Ave over W F Little Sioux | 1900 | 15 | Poor |
| Roosevelt Ave over Dd | 1900 | 15 | Poor |
| Ritchie Rd over Mud Creek | 1948 | 15 | Poor |
| 190TH St over Mink Creek | 1947 | 15 | Poor |
| Otter Ave over Willow Creek | 1949 | 15 | Poor |
| 120TH St over Indian Creek | 1900 | 15 | Poor |
| 235TH St over Broken Kettle Ck | 1900 | 15 | Poor |
| 300TH St over Creek | 1956 | 11 | Poor |
| 280TH St over Dry Branch | 1900 | 11 | Poor |
| 320TH St over Mud Creek | 1900 | 11 | Poor |
| 320TH St over Big Whiskey Creek | 1900 | 11 | Poor |
| 240TH St over Big Whiskey Slough | 1953 | 11 | Poor |
| 260TH St over Johns Creek | 1900 | 11 | Poor |
| 260TH over Johns Creek | 1966 | 11 | Poor |
| 270TH St over Carter Creek | 1900 | 11 | Poor |
| Fawn Ave over Broken Kettle Creek | 1953 | 11 | Poor |
| Evergreen Ave over Drainage | 1900 | 11 | Poor |
| Diamond Ave over Westfield Creek | 1900 | 11 | Poor |
| Concord Ave over Unnamed Creek | 1949 | 11 | Poor |
| Local over Deep Creek | 1941 | 11 | Poor |
| 150TH St over Broken Kettle Creek | 1952 | 11 | Poor |
| 240TH St over Mud Creek | 1956 | 5 | Poor |
| 240TH St over Perry Creek | 1900 | 5 | Poor |
| Granite Ave over Perry Creek | 1952 | 5 | Poor |
| 200TH St over Clear Creek | 1946 | 5 | Poor |
| Marble Ave. over Plymouth Creek | 1946 | 5 | Poor |
| Evergreen Ave over Indian Creek | 1961 | 5 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 75 over Stream | 1999 | 18,200 | Fair |
| US 75 over Stream | 2019 | 14,900 | Good |
| US 75 over Stream | 2019 | 14,900 | Good |
| US 75 over Stream | 2019 | 14,900 | Good |
| US 75 over Stream | 2019 | 14,900 | Good |
| US 75 over Stream | 1926 | 14,000 | Poor |
| US 75 over Dry Creek | 2023 | 14,000 | Good |
| US 75 over Dry Creek | 2023 | 14,000 | Good |
| US 75 over Dry Creek | 2023 | 14,000 | Good |
| US 75 over Drainage Ditch | 2023 | 14,000 | Good |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Iowa: Iowa bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.