US Bridges

Mooney Flat Road over Deer Creek

Fair

Nevada County, California · 1.5 MI North of Route 20 · Structure no. 17C0016

Built
1956
69 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
165 ft
2 main spans
Daily traffic
606
2014 count
Owner
County
County Highway Agency

About this bridge

Mooney Flat Road over Deer Creek is a steel stringer/multi-beam or girder carrying Mooney Flat Road over Deer Creek in Nevada County, California. It was built in 1956, so it is 69 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 606 vehicles a day, roughly 2% of them trucks, projected to reach 1,073 by 2041. The structure is 165 ft (50.3 m) long and 29 ft wide. If it were closed, the detour would be 5.6 mi (9 km).

Location

Open in Google Maps
CarriesMooney Flat Road
CrossesDeer Creek
Location1.5 MI North of Route 20
RouteCounty Highway 0
CountyNevada County
StateCalifornia
Coordinates39.2239, -121.27032
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.
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 inspectionMarch 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating48.2 US tons
Inventory rating37.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadH 20
Structure length165 ft (50.3 m)
Longest span81 ft (24.6 m)
Deck width29 ft (8.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic606 (2014)
Projected traffic1,073 by 2041
Trucks2%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5.6 mi (9 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 Mooney Flat Road over Deer Creek built?

It was built in 1956, making it 69 years old in 2025.

What condition is Mooney Flat Road over Deer 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 March 2023.

How much traffic does Mooney Flat Road over Deer Creek carry?

About 606 vehicles per day (2014 count), of which roughly 2% are trucks.

How long is Mooney Flat Road over Deer Creek?

The structure is 165 ft (50.3 m) long with a longest span of 81 ft (24.6 m) and a deck 29 ft wide.

Who owns Mooney Flat Road over Deer Creek?

It is owned by the County Highway Agency.