US Bridges

Mckay Alto Road over Whetstone Creek

Fair

Columbia County, Washington · 0.14 N JCT 2010 · Structure no. 084598000000000

Built
1970
55 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
36 ft
1 main span
Daily traffic
350
2020 count
Owner
County
County Highway Agency

About this bridge

Mckay Alto Road over Whetstone Creek is a steel stringer/multi-beam or girder carrying Mckay Alto Road over Whetstone Creek in Columbia County, Washington. It was built in 1970, so it is 55 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 350 vehicles a day, roughly 15% of them trucks, projected to reach 500 by 2042. The structure is 36 ft (11 m) long and 29 ft wide. If it were closed, the detour would be 16.8 mi (27 km).

Location

Open in Google Maps
CarriesMckay Alto Road
CrossesWhetstone Creek
Location0.14 N JCT 2010
RouteCounty Highway 92090
CountyColumbia County
StateWashington
Coordinates46.30308, -118.17208
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating29.7 US tons
Inventory rating22.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadUnknown
Structure length36 ft (11 m)
Longest span34 ft (10.5 m)
Deck width29 ft (8.8 m)
Roadway width27 ft (8.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic350 (2020)
Projected traffic500 by 2042
Trucks15%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.8 mi (27 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedOther structural work, including hydraulic replacements
Estimated improvement cost$445,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mckay Alto Road over Whetstone Creek built?

It was built in 1970, making it 55 years old in 2025.

What condition is Mckay Alto Road over Whetstone 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 October 2024.

How much traffic does Mckay Alto Road over Whetstone Creek carry?

About 350 vehicles per day (2020 count), of which roughly 15% are trucks.

How long is Mckay Alto Road over Whetstone Creek?

The structure is 36 ft (11 m) long with a longest span of 34 ft (10.5 m) and a deck 29 ft wide.

Who owns Mckay Alto Road over Whetstone Creek?

It is owned by the County Highway Agency.