US Bridges

IRR US 70 over Black Rock Wash

Fair

Graham County, Arizona · 32.7 MI W JCT US 191 · Structure no. 00545

Built
1932
93 years old, rebuilt 1959
Condition
Fair
inspected August 2023
Type
Tee Beam
Concrete
Length
207 ft
4 main spans
Daily traffic
3,521
2022 count
Owner
State
State Highway Agency

About this bridge

IRR US 70 over Black Rock Wash is a concrete tee beam carrying IRR US 70 over Black Rock Wash in Graham County, Arizona. It was built in 1932 and reconstructed in 1959, so it is 93 years old, older than the Arizona average of 47.8 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 3,521 vehicles a day, roughly 28% of them trucks, projected to reach 3,531 by 2042. The structure is 207 ft (63.1 m) long and 46 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

Open in Google Maps
CarriesIRR US 70
CrossesBlack Rock Wash
Location32.7 MI W JCT US 191
RouteU.S. Route 70
CountyGraham County
StateArizona
Coordinates33.03493, -109.96094
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating53 US tons
Inventory rating32 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length207 ft (63.1 m)
Longest span40 ft (12.2 m)
Deck width46 ft (14 m)
Roadway width43 ft (13.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,521 (2022)
Projected traffic3,531 by 2042
Trucks28%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.8 mi (159 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2,000 (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was IRR US 70 over Black Rock Wash built?

It was built in 1932, making it 93 years old in 2025. It was reconstructed in 1959.

What condition is IRR US 70 over Black Rock Wash 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 August 2023.

How much traffic does IRR US 70 over Black Rock Wash carry?

About 3,521 vehicles per day (2022 count), of which roughly 28% are trucks.

How long is IRR US 70 over Black Rock Wash?

The structure is 207 ft (63.1 m) long with a longest span of 40 ft (12.2 m) and a deck 46 ft wide.

Who owns IRR US 70 over Black Rock Wash?

It is owned by the State Highway Agency.