US Bridges

State Route 70 over Mill Creek

Fair

Butte County, California · 03-BUT-070-42.06 · Structure no. 12 0205

Built
2021
4 years old
Condition
Fair
inspected April 2023
Type
Girder and Floorbeam System
Prestressed Concrete
Length
90 ft
1 main span
Daily traffic
1,700
2020 count
Owner
State
State Highway Agency

About this bridge

State Route 70 over Mill Creek is a prestressed concrete girder and floorbeam system carrying State Route 70 over Mill Creek in Butte County, California. It was built in 2021, so it is 4 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 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 1,700 vehicles a day, roughly 11% of them trucks, projected to reach 2,210 by 2042. The structure is 90 ft (27.4 m) long and 48 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesState Route 70
CrossesMill Creek
Location03-BUT-070-42.06
RouteState Highway 70
CountyButte County
StateCalifornia
Coordinates39.80467, -121.43944
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionApril 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry8: Equal to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length90 ft (27.4 m)
Longest span86 ft (26.1 m)
Deck width48 ft (14.6 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,700 (2020)
Projected traffic2,210 by 2042
Trucks11%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was State Route 70 over Mill Creek built?

It was built in 2021, making it 4 years old in 2025.

What condition is State Route 70 over Mill Creek 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 April 2023.

How much traffic does State Route 70 over Mill Creek carry?

About 1,700 vehicles per day (2020 count), of which roughly 11% are trucks.

How long is State Route 70 over Mill Creek?

The structure is 90 ft (27.4 m) long with a longest span of 86 ft (26.1 m) and a deck 48 ft wide.

Who owns State Route 70 over Mill Creek?

It is owned by the State Highway Agency.