CR 161 over Bay of Thunder Lake
Cass County, Minnesota · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- CR 161 over Bay of Thunder Lake in Cass County, Minnesota, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1915, making it 110 years old at the 2025 inventory.
- It carries about 44 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 38 of the 85 inventoried bridges in Cass County rated fair (44.7%); 7 (8.2%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: superstructure 6 to 5.
- 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 → (46.96529, -93.94215)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 6 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 24 ft |
| Location | 1.1 Mi N of Jct Th 6 |
| NBI structure number | 1660 |
| Condition class | Fair |
| Traffic status (item 41) | Posted for load |
| 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 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.