US Bridges

Quincy-La Porte RD over Middle Fork Feather Riv

Fair

Plumas County, California · 7.9 MI S/W SH 70 · Structure no. 09C0004

Built
1975
50 years old
Condition
Fair
inspected October 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
269 ft
3 main spans
Daily traffic
180
2019 count
Owner
County
County Highway Agency

About this bridge

Quincy-La Porte RD over Middle Fork Feather Riv is a prestressed concrete continuous box beam or girders - multiple carrying Quincy-La Porte RD over Middle Fork Feather Riv in Plumas County, California. It was built in 1975, so it is 50 years old, younger 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 180 vehicles a day, roughly 5% of them trucks, projected to reach 209 by 2044. The structure is 269 ft (82 m) long and 29 ft wide. If it were closed, the detour would be 65.2 mi (105 km).

Location

Open in Google Maps
CarriesQuincy-La Porte RD
CrossesMiddle Fork Feather Riv
Location7.9 MI S/W SH 70
RouteCounty Highway 0
CountyPlumas County
StateCalifornia
Coordinates39.85924, -120.84982
Functional classRural Major 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 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 geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71.1 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length269 ft (82 m)
Longest span106 ft (32.3 m)
Deck width29 ft (8.7 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic180 (2019)
Projected traffic209 by 2044
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed65.2 mi (105 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Quincy-La Porte RD over Middle Fork Feather Riv built?

It was built in 1975, making it 50 years old in 2025.

What condition is Quincy-La Porte RD over Middle Fork Feather Riv 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 2023.

How much traffic does Quincy-La Porte RD over Middle Fork Feather Riv carry?

About 180 vehicles per day (2019 count), of which roughly 5% are trucks.

How long is Quincy-La Porte RD over Middle Fork Feather Riv?

The structure is 269 ft (82 m) long with a longest span of 106 ft (32.3 m) and a deck 29 ft wide.

Who owns Quincy-La Porte RD over Middle Fork Feather Riv?

It is owned by the County Highway Agency.