T 421 over Redwood River
Lyon County, Minnesota · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- T 421 over Redwood River in Lyon 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 1958, making it 67 years old at the 2025 inventory.
- It carries about 12 vehicles a day (traffic count year 1992).
- Its listed owner is a town or township highway agency.
- It is one of 51 of the 234 inventoried bridges in Lyon County rated fair (21.8%); 6 (2.6%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2023, 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 → (44.43062, -95.84648)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Timber stringer or multi-beam girder |
| Length | about 80 ft |
| Location | 0.9 Mi S of Jct Th 19 |
| NBI structure number | 255 |
| Condition class | Fair |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | October 2023 |
| 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 Lyon County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 59 over Redwood River | 1950 | 9,500 | Fair |
| Mn 19 over Redwood River | 1931 | 8,800 | Fair |
| Mn 19 over Redwood River | 1975 | 8,300 | Fair |
| Mn 23 over Ditch | 1999 | 5,910 | Good |
| Mn 23 over Redwood River | 1973 | 5,204 | Fair |
| US 59 over Redwood R Diversion Chan | 1962 | 5,200 | Fair |
All bridges nearby: Lyon County, MN bridge conditions · every bridge in Lyon County · Minnesota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.