FDR3500 over E Br Ontonagon River
Houghton County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- FDR3500 over E Br Ontonagon River in Houghton County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 2021, making it 4 years old at the 2025 inventory.
- It carries about 20 vehicles a day (traffic count year 2021).
- It is one of 19 of the 59 inventoried bridges in Houghton County rated fair (32.2%); 2 (3.4%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated September 2024, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (46.44602, -88.76992)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Timber slab |
| Length | about 30 ft |
| Location | 8 Mi SW of Sidnaw |
| NBI structure number | 090704000034743 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Houghton County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Us-41&m-26 Rr(abn) over Portage Lake & EB M-26 | 1960 | 24,754 | Fair |
| US-41 over Pilgrim River | 1916 | 5,543 | Fair |
| M-26 over Quincy Creek | 2021 | 5,200 | Good |
| US-41 over Sturgeon River Slough | 1956 | 3,985 | Fair |
| US-41 over Snake River | 1934 | 3,883 | Fair |
| US-41 over Backwater Portage River | 1929 | 3,883 | Fair |
All bridges nearby: Houghton County, MI bridge conditions · every bridge in Houghton County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.