US Bridges

Rockport Cascade over Cascade River

Fair

Skagit County, Washington · 0.04 S JCT Cascade RD · Structure no. 082136000000000

Built
1967
58 years old
Condition
Fair
inspected June 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
180 ft
3 main spans
Daily traffic
294
2023 count
Owner
County
County Highway Agency

About this bridge

Rockport Cascade over Cascade River is a prestressed concrete continuous stringer/multi-beam or girder carrying Rockport Cascade over Cascade River in Skagit County, Washington. It was built in 1967, so it is 58 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 294 vehicles a day, roughly 7% of them trucks, projected to reach 359 by 2043. The structure is 180 ft (54.9 m) long and 30 ft wide. If it were closed, the detour would be 21.1 mi (34 km).

Location

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CarriesRockport Cascade
CrossesCascade River
Location0.04 S JCT Cascade RD
RouteCounty Highway 8700
CountySkagit County
StateWashington
Coordinates48.52653, -121.41526
Functional classRural Minor Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.1 US tons
Inventory rating26.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length180 ft (54.9 m)
Longest span140 ft (42.7 m)
Deck width30 ft (9.2 m)
Roadway width26 ft (8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic294 (2023)
Projected traffic359 by 2043
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed21.1 mi (34 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 proposedDeck rehabilitation with only incidental widening
Estimated improvement cost$2.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Rockport Cascade over Cascade River built?

It was built in 1967, making it 58 years old in 2025.

What condition is Rockport Cascade over Cascade River in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in June 2023.

How much traffic does Rockport Cascade over Cascade River carry?

About 294 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is Rockport Cascade over Cascade River?

The structure is 180 ft (54.9 m) long with a longest span of 140 ft (42.7 m) and a deck 30 ft wide.

Who owns Rockport Cascade over Cascade River?

It is owned by the County Highway Agency.