Iron Bridge Road over Sturgeon River
Charlevoix County, Michigan · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Iron Bridge Road over Sturgeon River in Charlevoix County, Michigan, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 2 (critical condition) on the 0-9 scale.
- It was built in 1900, making it 125 years old at the 2025 inventory.
- It carries about 3 vehicles a day (traffic count year 2001).
- Its listed owner is the county highway agency.
- It is one of 2 of the 18 inventoried bridges in Charlevoix County rated poor (11.1%); 2 (11.1%) are rated poor.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (45.14414, -84.74232)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 2 | Critical condition |
| Substructure | 5 | Fair condition |
Bridge details
| Structure | Steel through truss |
| Length | about 41 ft |
| Location | 10 Mi East of Boyne Falls |
| NBI structure number | 000000000001484 |
| Condition class | Poor |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Charlevoix County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US-31 over Pine River | 1949 | 15,321 | Fair |
| US-131 over Boyne River | 1947 | 6,736 | Fair |
| M-75|s East St over Boyne River | 1974 | 6,546 | Fair |
| Park Street over Boyne River | 1991 | 5,000 | Fair |
| M-32|water St over S Arm Lake Charlevoix | 1959 | 4,600 | Fair |
| Lake Street over Boyne River | 1959 | 3,000 | Fair |
All bridges nearby: Charlevoix County, MI bridge conditions · every bridge in Charlevoix County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.