US Bridges

Keefer RD over Keefer Slough

Fair

Butte County, California · 2.5 MI E/O SH 99 · Structure no. 12C0282

Built
1930
95 years old
Condition
Fair
inspected July 2024
Type
Slab
Concrete Continuous
Length
41 ft
4 main spans
Daily traffic
17,020
2015 count
Owner
County
County Highway Agency

About this bridge

Keefer RD over Keefer Slough is a concrete continuous slab carrying Keefer RD over Keefer Slough in Butte County, California. It was built in 1930, so it is 95 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 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 17,020 vehicles a day, roughly 15% of them trucks, projected to reach 26,018 by 2042. The structure is 41 ft (12.4 m) long and 22 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesKeefer RD
CrossesKeefer Slough
Location2.5 MI E/O SH 99
RouteCounty Highway 0
CountyButte County
StateCalifornia
Coordinates39.81911, -121.8736
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourCountermeasures installed to correct a previously existing problem
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating29.7 US tons
Inventory rating17.9 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadUnknown
Structure length41 ft (12.4 m)
Longest span10 ft (3 m)
Deck width22 ft (6.7 m)
Roadway width20 ft (6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,020 (2015)
Projected traffic26,018 by 2042
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed9.9 mi (16 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 Keefer RD over Keefer Slough built?

It was built in 1930, making it 95 years old in 2025.

What condition is Keefer RD over Keefer Slough 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 July 2024.

How much traffic does Keefer RD over Keefer Slough carry?

About 17,020 vehicles per day (2015 count), of which roughly 15% are trucks.

How long is Keefer RD over Keefer Slough?

The structure is 41 ft (12.4 m) long with a longest span of 10 ft (3 m) and a deck 22 ft wide.

Who owns Keefer RD over Keefer Slough?

It is owned by the County Highway Agency.