Irr Bia Rte 22 over Trib to Red Butte Bay
Mercer County, North Dakota · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irr Bia Rte 22 over Trib to Red Butte Bay in Mercer County, North Dakota, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 2 (critical condition) on the 0-9 scale.
- It was built in 1960, making it 65 years old at the 2025 inventory.
- It carries about 200 vehicles a day (traffic count year 2020).
- It is one of 4 of the 71 inventoried bridges in Mercer County rated poor (5.6%); 4 (5.6%) are rated poor.
- Its traffic status in the 2025 inventory is open, posting recommended but not legally implemented (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated August 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 → (47.51209, -102.12863)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 2 | 2 | Critical condition |
Bridge details
| Structure | Steel culvert |
| Length | about 53 ft |
| Location | SE Lake Sakakawea |
| NBI structure number | 0000A04301B0500 |
| Condition class | Poor |
| Traffic status (item 41) | Open, posting recommended but not legally implemented |
| Last inspection (item 90) | August 2024 |
| Inspection interval (item 91) | 12 months |
| Scour (item 113) | 4: foundations stable, field review says exposed foundations need protection |
Source: FHWA National Bridge Inventory, 2025 data as reported by the North Dakota department of transportation.
Busiest bridges in Mercer County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Nd Highway 49 over Creek | 1967 | 3,730 | Fair |
| Nd Highway 49 over Knife River | 2016 | 3,400 | Good |
| Nd Highway 49 over Coyote Creek | 2016 | 2,745 | Good |
| Nd Highway 49 over Brush Creek | 2016 | 2,745 | Good |
| Nd Highway 200 over Knife River Overflow | 1952 | 2,300 | Fair |
| Nd Highway 200 over Knife River | 1966 | 2,280 | Fair |
All bridges nearby: Mercer County, ND bridge conditions · every bridge in Mercer County · North Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.