SH 21 over Mores Creek;big Gulch
GoodBoise County, Idaho · 5.7 S. Idaho City · Structure no. 000000000012865
- Built
- 1990
- 35 years old
- Condition
- Good
- inspected October 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete
- Length
- 57 ft
- 1 main span
- Daily traffic
- 2,000
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
SH 21 over Mores Creek;big Gulch is a prestressed concrete stringer/multi-beam or girder carrying SH 21 over Mores Creek;big Gulch in Boise County, Idaho. It was built in 1990, so it is 35 years old, younger than the Idaho average of 45.3 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 2,000 vehicles a day, roughly 18% of them trucks, projected to reach 3,000 by 2042. The structure is 57 ft (17.4 m) long and 40 ft wide. If it were closed, the detour would be 24.9 mi (40 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was SH 21 over Mores Creek;big Gulch built?
It was built in 1990, making it 35 years old in 2025.
What condition is SH 21 over Mores Creek;big Gulch in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in October 2023.
How much traffic does SH 21 over Mores Creek;big Gulch carry?
About 2,000 vehicles per day (2023 count), of which roughly 18% are trucks.
How long is SH 21 over Mores Creek;big Gulch?
The structure is 57 ft (17.4 m) long with a longest span of 54 ft (16.6 m) and a deck 40 ft wide.
Who owns SH 21 over Mores Creek;big Gulch?
It is owned by the State Highway Agency.