M 58 over Stony Brook
Cass County, Minnesota · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- M 58 over Stony Brook in Cass County, Minnesota, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1972, making it 53 years old at the 2025 inventory.
- It carries about 50 vehicles a day (traffic count year 2016).
- Its listed owner is a city or municipal highway agency.
- It is one of 7 of the 85 inventoried bridges in Cass County rated poor (8.2%); 7 (8.2%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- It was rated fair in the 2024 inventory and is now poor (superstructure 5 to 3).
- Its most recent inspection on record is dated September 2024, on a 12-month routine inspection cycle.
- 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 → (46.52002, -94.35265)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 3 | Serious condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 41 ft |
| Location | In Lake Shore |
| NBI structure number | L5920 |
| Condition class | Poor |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | September 2024 |
| Inspection interval (item 91) | 12 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 Minnesota department of transportation.
Busiest bridges in Cass County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Mn 210 over Gull River | 1952 | 9,175 | Fair |
| Mn 371 over Shingobee River | 1992 | 8,423 | Fair |
| Mn 210 over Mosquito Creek | 2002 | 6,510 | Fair |
| Mn 210 over Pillager Creek | 1953 | 6,510 | Fair |
| Mn 210 over Seven Mile Creek | 1953 | 6,510 | Fair |
| Mn 371 over S Fk Pine River | 1992 | 6,346 | Good |
All bridges nearby: Cass County, MN bridge conditions · every bridge in Cass County · Minnesota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.