US Bridges

Port Wine Road over Slate Creek Overflow

Fair

Plumas County, California · 2 MI Se/O Quin-Laport RD · Structure no. 09C0027

Built
1936
89 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
50 ft
3 main spans
Daily traffic
30
2019 count
Owner
County
County Highway Agency

About this bridge

Port Wine Road over Slate Creek Overflow is a steel continuous stringer/multi-beam or girder carrying Port Wine Road over Slate Creek Overflow 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 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 30 vehicles a day, projected to reach 53 by 2044. The structure is 50 ft (15.2 m) long and 14 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesPort Wine Road
CrossesSlate Creek Overflow
Location2 MI Se/O Quin-Laport RD
RouteCounty Highway 0
CountyPlumas County
StateCalifornia
Coordinates39.66164, -120.96459
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
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
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 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 rating62.5 US tons
Inventory rating44.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckWood or timber
Main spans3
Design loadUnknown
Structure length50 ft (15.2 m)
Longest span22 ft (6.7 m)
Deck width14 ft (4.2 m)
Roadway width12 ft (3.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic30 (2019)
Projected traffic53 by 2044
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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 Port Wine Road over Slate Creek Overflow built?

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

What condition is Port Wine Road over Slate Creek Overflow 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 Port Wine Road over Slate Creek Overflow carry?

About 30 vehicles per day (2019 count).

How long is Port Wine Road over Slate Creek Overflow?

The structure is 50 ft (15.2 m) long with a longest span of 22 ft (6.7 m) and a deck 14 ft wide.

Who owns Port Wine Road over Slate Creek Overflow?

It is owned by the County Highway Agency.