US Bridges

Ryan Allen Road over Rock Creek

Good

Skamania County, Washington · 1.08 N JCT 2nd St. · Structure no. 084752000000000

Built
1972
53 years old
Condition
Good
inspected August 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
152 ft
1 main span
Daily traffic
1,648
2024 count
Owner
County
County Highway Agency

About this bridge

Ryan Allen Road over Rock Creek is a prestressed concrete stringer/multi-beam or girder carrying Ryan Allen Road over Rock Creek in Skamania County, Washington. It was built in 1972, so it is 53 years old, older 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 1,648 vehicles a day, roughly 9% of them trucks, projected to reach 611 by 2042. The structure is 152 ft (46.3 m) long and 31 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesRyan Allen Road
CrossesRock Creek
Location1.08 N JCT 2nd St.
RouteCounty Highway 20380
Coordinates45.69833, -121.905
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.4 US tons
Inventory rating24.3 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length152 ft (46.3 m)
Longest span106 ft (32.3 m)
Deck width31 ft (9.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,648 (2024)
Projected traffic611 by 2042
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$5.8 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Ryan Allen Road over Rock Creek built?

It was built in 1972, making it 53 years old in 2025.

What condition is Ryan Allen Road over Rock Creek 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 August 2024.

How much traffic does Ryan Allen Road over Rock Creek carry?

About 1,648 vehicles per day (2024 count), of which roughly 9% are trucks.

How long is Ryan Allen Road over Rock Creek?

The structure is 152 ft (46.3 m) long with a longest span of 106 ft (32.3 m) and a deck 31 ft wide.

Who owns Ryan Allen Road over Rock Creek?

It is owned by the County Highway Agency.