US Bridges

Parker Dam Road over Colorado River

FairPosted for load

San Bernardino County, California · 6 M NE of Parker Az · Structure no. 0300-0048-5

Built
1934
91 years old
Condition
Fair
inspected December 2024
Type
Girder and Floorbeam System
Concrete
Length
66 ft
1 main span
Daily traffic
360
2012 count
Owner
Federal
Bureau of Reclamation

About this bridge

Parker Dam Road over Colorado River is a concrete girder and floorbeam system carrying Parker Dam Road over Colorado River in San Bernardino County, California. It was built in 1934, so it is 91 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. Its operating status is: posted for load restriction.

It carries about 360 vehicles a day, projected to reach 600 by 2034. The structure is 66 ft (20 m) long and 25 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

Open in Google Maps
CarriesParker Dam Road
CrossesColorado River
Location6 M NE of Parker Az
CountySan Bernardino County
StateCalifornia
Coordinates34.29647, -114.13983
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
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 protection9 ExcellentNo problems noted.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating59.4 US tons
Inventory rating35.6 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length66 ft (20 m)
Longest span50 ft (15.2 m)
Deck width25 ft (7.5 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic360 (2012)
Projected traffic600 by 2034
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerBureau of Reclamation
Maintained byBureau of Reclamation
Historic statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Parker Dam Road over Colorado River built?

It was built in 1934, making it 91 years old in 2025.

What condition is Parker Dam Road over Colorado River 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 December 2024.

How much traffic does Parker Dam Road over Colorado River carry?

About 360 vehicles per day (2012 count).

How long is Parker Dam Road over Colorado River?

The structure is 66 ft (20 m) long with a longest span of 50 ft (15.2 m) and a deck 25 ft wide.

Who owns Parker Dam Road over Colorado River?

It is owned by the Bureau of Reclamation.