HWY 91 N over Big Hole River 041
PoorClosed to trafficBeaverhead County, Montana · 22M N Dillon · Structure no. L01311022+02001
- Built
- 1940
- 85 years old
- Condition
- Poor
- inspected July 2024
- Type
- Truss - Thru
- Steel
- Length
- 240 ft
- 1 main span
- Daily traffic
- 158
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
HWY 91 N over Big Hole River 041 is a steel truss - thru carrying HWY 91 N over Big Hole River 041 in Beaverhead County, Montana. It was built in 1940, so it is 85 years old, older than the Montana average of 47 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: closed to all traffic.
It carries about 158 vehicles a day, roughly 2% of them trucks, projected to reach 166 by 2043. The structure is 240 ft (73.1 m) long and 21 ft wide. If it were closed, the detour would be 9.9 mi (16 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Superstructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Substructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was HWY 91 N over Big Hole River 041 built?
It was built in 1940, making it 85 years old in 2025.
What condition is HWY 91 N over Big Hole River 041 in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2024.
How much traffic does HWY 91 N over Big Hole River 041 carry?
About 158 vehicles per day (2023 count), of which roughly 2% are trucks.
How long is HWY 91 N over Big Hole River 041?
The structure is 240 ft (73.1 m) long with a longest span of 148 ft (45.1 m) and a deck 21 ft wide.
Who owns HWY 91 N over Big Hole River 041?
It is owned by the State Highway Agency.