US Bridges

IRR BIA RTE N6720 over Dinnebito Wash

FairPosted for load

Coconino County, Arizona · 5 MI SW of Sand Springs · Structure no. 00000000000N309

Built
1974
51 years old
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
51 ft
1 main span
Daily traffic
90
2023 count
Owner
Federal
Bureau of Indian Affairs

About this bridge

IRR BIA RTE N6720 over Dinnebito Wash is a steel stringer/multi-beam or girder carrying IRR BIA RTE N6720 over Dinnebito Wash in Coconino County, Arizona. It was built in 1974, so it is 51 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. Its operating status is: posted for load restriction.

It carries about 90 vehicles a day, roughly 3% of them trucks, projected to reach 92 by 2043. The structure is 51 ft (15.4 m) long and 14 ft wide. If it were closed, the detour would be 24.9 mi (40 km).

Location

Open in Google Maps
CarriesIRR BIA RTE N6720
CrossesDinnebito Wash
Location5 MI SW of Sand Springs
RouteFederal Lands Road N6720
CountyCoconino County
StateArizona
Coordinates35.65492, -110.94797
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.
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 protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating16 US tons
Inventory rating14 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckOpen grating
Main spans1
Design loadUnknown
Structure length51 ft (15.4 m)
Longest span49 ft (14.9 m)
Deck width14 ft (4.3 m)
Roadway width13 ft (4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic90 (2023)
Projected traffic92 by 2043
Trucks3%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed24.9 mi (40 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerBureau of Indian Affairs
Maintained byBureau of Indian Affairs
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$821,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was IRR BIA RTE N6720 over Dinnebito Wash built?

It was built in 1974, making it 51 years old in 2025.

What condition is IRR BIA RTE N6720 over Dinnebito 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 March 2023.

How much traffic does IRR BIA RTE N6720 over Dinnebito Wash carry?

About 90 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is IRR BIA RTE N6720 over Dinnebito Wash?

The structure is 51 ft (15.4 m) long with a longest span of 49 ft (14.9 m) and a deck 14 ft wide.

Who owns IRR BIA RTE N6720 over Dinnebito Wash?

It is owned by the Bureau of Indian Affairs.