US Bridges

Airport RD over Nine Mile Slough

Good

Harney County, Oregon · 000 JCT or 78 Steens HWY · Structure no. 24143 C11500002

Built
2022
3 years old
Condition
Good
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
32 ft
1 main span
Daily traffic
400
2020 count
Owner
County
County Highway Agency

About this bridge

Airport RD over Nine Mile Slough is a steel stringer/multi-beam or girder carrying Airport RD over Nine Mile Slough in Harney County, Oregon. It was built in 2022, so it is 3 years old, younger than the Oregon average of 49.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 400 vehicles a day, roughly 20% of them trucks, projected to reach 480 by 2025. The structure is 32 ft (9.8 m) long and 32 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesAirport RD
CrossesNine Mile Slough
Location000 JCT or 78 Steens HWY
RouteCounty Highway C0115
StateOregon
Coordinates43.58564, -118.98082
Functional classRural Minor Collector

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating37.8 US tons
Inventory rating22.8 US tons

Structure

MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHL 93
Structure length32 ft (9.8 m)
Longest span31 ft (9.4 m)
Deck width32 ft (9.9 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic400 (2020)
Projected traffic480 by 2025
Trucks20%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 Airport RD over Nine Mile Slough built?

It was built in 2022, making it 3 years old in 2025.

What condition is Airport RD over Nine Mile Slough in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in September 2024.

How much traffic does Airport RD over Nine Mile Slough carry?

About 400 vehicles per day (2020 count), of which roughly 20% are trucks.

How long is Airport RD over Nine Mile Slough?

The structure is 32 ft (9.8 m) long with a longest span of 31 ft (9.4 m) and a deck 32 ft wide.

Who owns Airport RD over Nine Mile Slough?

It is owned by the County Highway Agency.