US Bridges

HWY 100 over Oneonta Gorge Creek

Fair

Multnomah County, Oregon · 2.2 MI E Multnomah Falls · Structure no. 07108A125 02193

Built
1948
77 years old
Condition
Fair
inspected September 2023
Type
Tee Beam
Concrete
Length
48 ft
1 main span
Daily traffic
901
2022 count
Owner
State
State Highway Agency

About this bridge

HWY 100 over Oneonta Gorge Creek is a concrete tee beam carrying HWY 100 over Oneonta Gorge Creek in Multnomah County, Oregon. It was built in 1948, so it is 77 years old, older than the Oregon average of 49.9 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 901 vehicles a day, roughly 4% of them trucks, projected to reach 1,200 by 2042. The structure is 48 ft (14.6 m) long and 35 ft wide. If it were closed, the detour would be 49.7 mi (80 km).

Location

Open in Google Maps
CarriesHWY 100
CrossesOneonta Gorge Creek
Location2.2 MI E Multnomah Falls
RouteState Highway 30
CountyMultnomah County
StateOregon
Coordinates45.58968, -122.07547
Functional classRural Major 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating23.9 US tons
Inventory rating18.5 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 15
Structure length48 ft (14.6 m)
Longest span48 ft (14.6 m)
Deck width35 ft (10.7 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic901 (2022)
Projected traffic1,200 by 2042
Trucks4%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed49.7 mi (80 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was HWY 100 over Oneonta Gorge Creek built?

It was built in 1948, making it 77 years old in 2025.

What condition is HWY 100 over Oneonta Gorge 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 September 2023.

How much traffic does HWY 100 over Oneonta Gorge Creek carry?

About 901 vehicles per day (2022 count), of which roughly 4% are trucks.

How long is HWY 100 over Oneonta Gorge Creek?

The structure is 48 ft (14.6 m) long with a longest span of 48 ft (14.6 m) and a deck 35 ft wide.

Who owns HWY 100 over Oneonta Gorge Creek?

It is owned by the State Highway Agency.