US 101 over Slough
GoodMason County, Washington · 1.6 S JCT SR 106 · Structure no. 0012672A0000000
- Built
- 1985
- 40 years old
- Condition
- Good
- inspected July 2021
- Type
- Slab
- Prestressed Concrete
- Length
- 160 ft
- 4 main spans
- Daily traffic
- 7,648
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US 101 over Slough is a prestressed concrete slab carrying US 101 over Slough in Mason County, Washington. It was built in 1985, so it is 40 years old, younger than the Washington average of 49.8 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 7,648 vehicles a day, roughly 6% of them trucks, projected to reach 9,983 by 2039. The structure is 160 ft (48.8 m) long and 41 ft wide. If it were closed, the detour would be 6.8 mi (11 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 | 7 Good | Some minor problems. |
| 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 US 101 over Slough built?
It was built in 1985, making it 40 years old in 2025.
What condition is US 101 over Slough 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 July 2021.
How much traffic does US 101 over Slough carry?
About 7,648 vehicles per day (2023 count), of which roughly 6% are trucks.
How long is US 101 over Slough?
The structure is 160 ft (48.8 m) long with a longest span of 39 ft (11.9 m) and a deck 41 ft wide.
Who owns US 101 over Slough?
It is owned by the State Highway Agency.