US Bridges

Quartz Valley Road over Mill Creek

Fair

Siskiyou County, California · 0.1 MI W E. Quartz Valley · Structure no. 02C0066

Built
1980
45 years old
Condition
Fair
inspected June 2024
Type
Slab
Concrete Continuous
Length
83 ft
3 main spans
Daily traffic
395
2011 count
Owner
County
County Highway Agency

About this bridge

Quartz Valley Road over Mill Creek is a concrete continuous slab carrying Quartz Valley Road over Mill Creek in Siskiyou County, California. It was built in 1980, so it is 45 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 395 vehicles a day, roughly 5% of them trucks, projected to reach 489 by 2042. The structure is 83 ft (25.3 m) long and 25 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesQuartz Valley Road
CrossesMill Creek
Location0.1 MI W E. Quartz Valley
RouteCounty Highway 0
CountySiskiyou County
StateCalifornia
Coordinates41.58156, -122.96087
Functional classRural Minor 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
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJune 2024
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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating67.1 US tons
Inventory rating40.3 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length83 ft (25.3 m)
Longest span32 ft (9.8 m)
Deck width25 ft (7.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic395 (2011)
Projected traffic489 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 Quartz Valley Road over Mill Creek built?

It was built in 1980, making it 45 years old in 2025.

What condition is Quartz Valley Road 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 June 2024.

How much traffic does Quartz Valley Road over Mill Creek carry?

About 395 vehicles per day (2011 count), of which roughly 5% are trucks.

How long is Quartz Valley Road over Mill Creek?

The structure is 83 ft (25.3 m) long with a longest span of 32 ft (9.8 m) and a deck 25 ft wide.

Who owns Quartz Valley Road over Mill Creek?

It is owned by the County Highway Agency.