US Bridges

State Route 70 over North Fork Feather River

Fair

Plumas County, California · 02-PLU-070-16.54 · Structure no. 09 0009

Built
1934
91 years old
Condition
Fair
inspected June 2023
Type
Arch - Thru
Steel
Length
135 ft
1 main span
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 arch - thru carrying State Route 70 over North Fork Feather River in Plumas County, California. It was built in 1934, so it is 91 years old, older than the California average of 54.8 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 1,345 vehicles a day, roughly 21% of them trucks, projected to reach 1,530 by 2040. The structure is 135 ft (41.1 m) long and 31 ft wide. If it were closed, the detour would be 41 mi (66 km).

Location

Open in Google Maps
CarriesState Route 70
CrossesNorth Fork Feather River
Location02-PLU-070-16.54
RouteState Highway 70
CountyPlumas County
StateCalifornia
Coordinates40.01417, -121.22594
Functional classRural Minor Arterial

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 rating40 US tons
Inventory rating23.9 US tons

Structure

Structure typeArch - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length135 ft (41.1 m)
Longest span130 ft (39.6 m)
Deck width31 ft (9.5 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deck15 ft (4.7 m)

Traffic and service

Average daily traffic1,345 (2009)
Projected traffic1,530 by 2040
Trucks21%
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 1934, making it 91 years old in 2025.

What condition is State Route 70 over North Fork Feather 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 State Route 70 over North Fork Feather River carry?

About 1,345 vehicles per day (2009 count), of which roughly 21% are trucks.

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

The structure is 135 ft (41.1 m) long with a longest span of 130 ft (39.6 m) and a deck 31 ft wide.

Who owns State Route 70 over North Fork Feather River?

It is owned by the State Highway Agency.