US Bridges

State Route 70 over North Fork Feather River

Good

Plumas County, California · 02-PLU-070-5.58 · Structure no. 09 0003

Built
1936
89 years old
Condition
Good
inspected June 2023
Type
Truss - Thru
Steel
Length
361 ft
2 main spans
Daily traffic
1,345
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 70 over North Fork Feather River is a steel truss - thru carrying State Route 70 over North Fork Feather River in Plumas County, California. It was built in 1936, so it is 89 years old, older than the California average of 54.8 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 1,345 vehicles a day, roughly 14% of them trucks, projected to reach 1,530 by 2040. The structure is 361 ft (110 m) long and 27 ft wide. If it were closed, the detour would be 41 mi (66 km).

CarriesState Route 70
CrossesNorth Fork Feather River
Location02-PLU-070-5.58
RouteState Highway 70
Coordinates39.91796, -121.32156
Functional classRural Minor Arterial

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 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 evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
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 rating41.1 US tons
Inventory rating24.7 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans2 (+2 approach)
Design loadHS 15
Structure length361 ft (110 m)
Longest span120 ft (36.6 m)
Deck width27 ft (8.1 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,345 (2009)
Projected traffic1,530 by 2040
Trucks14%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed41 mi (66 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was State Route 70 over North Fork Feather River built?

It was built in 1936, making it 89 years old in 2025.

What condition is State Route 70 over North Fork Feather River 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 June 2023.

How much traffic does State Route 70 over North Fork Feather River carry?

About 1,345 vehicles per day (2009 count), of which roughly 14% are trucks.

How long is State Route 70 over North Fork Feather River?

The structure is 361 ft (110 m) long with a longest span of 120 ft (36.6 m) and a deck 27 ft wide.

Who owns State Route 70 over North Fork Feather River?

It is owned by the State Highway Agency.