US Bridges

Cascade River Road over North Fork Cascade River

Fair

Skagit County, Washington · 20.6 Miles East of Marble · Structure no. 9470004P0000000

Built
1979
46 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
51 ft
1 main span
Daily traffic
50
2019 count
Owner
Federal
National Park Service

About this bridge

Cascade River Road over North Fork Cascade River is a wood or timber stringer/multi-beam or girder carrying Cascade River Road over North Fork Cascade River in Skagit County, Washington. It was built in 1979, so it is 46 years old, younger 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 6 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 50 vehicles a day, roughly 1% of them trucks, projected to reach 100 by 2039. The structure is 51 ft (15.5 m) long and 13 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesCascade River Road
CrossesNorth Fork Cascade River
Location20.6 Miles East of Marble
RouteFederal Lands Road 101
Coordinates48.49203, -121.10811
Functional classRural Local

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating38 US tons
Inventory rating26 US tons

Structure

MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadH 15
Structure length51 ft (15.5 m)
Longest span48 ft (14.6 m)
Deck width13 ft (4.1 m)
Roadway width12 ft (3.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2019)
Projected traffic100 by 2039
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerNational Park Service
Maintained byNational Park Service
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost$9,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cascade River Road over North Fork Cascade River built?

It was built in 1979, making it 46 years old in 2025.

What condition is Cascade River Road over North Fork 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 October 2024.

How much traffic does Cascade River Road over North Fork Cascade River carry?

About 50 vehicles per day (2019 count), of which roughly 1% are trucks.

How long is Cascade River Road over North Fork Cascade River?

The structure is 51 ft (15.5 m) long with a longest span of 48 ft (14.6 m) and a deck 13 ft wide.

Who owns Cascade River Road over North Fork Cascade River?

It is owned by the National Park Service.