21 Mile Rd over Middle Branch River
Osceola County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- 21 Mile Rd over Middle Branch River in Osceola 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 1989, making it 36 years old at the 2025 inventory.
- It carries about 477 vehicles a day (traffic count year 2000).
- Its listed owner is the county highway agency.
- It is one of 60 of the 103 inventoried bridges in Osceola County rated fair (58.3%); 7 (6.8%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: deck 7 to 6.
- Its most recent inspection on record is dated July 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 → (44.1169, -85.16445)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 71 ft |
| Location | Section 16/21 T20N R7W |
| NBI structure number | 000000000008636 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Osceola County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US-131 NB over E Br Hersey River | 1957 | 12,782 | Fair |
| US-131 NB over Hersey Creek | 1985 | 11,841 | Fair |
| US-131 SB over Hersey Creek | 1985 | 11,841 | Fair |
| US-10 over Twin Creek | 1997 | 11,184 | Good |
| US-10 over Hersey River | 1958 | 6,569 | Fair |
| US-131 NB over Johnson Creek | 1984 | 6,391 | Fair |
All bridges nearby: Osceola County, MI bridge conditions · every bridge in Osceola County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.