US Bridges

Mission Creek RD over Mission Creek

Good

Mason County, Washington · 0.40 N JCT SR 300 · Structure no. 085884000000000

Built
1991
34 years old
Condition
Good
inspected June 2024
Type
Tee Beam
Concrete
Length
58 ft
1 main span
Daily traffic
827
2020 count
Owner
County
County Highway Agency

About this bridge

Mission Creek RD over Mission Creek is a concrete tee beam carrying Mission Creek RD over Mission Creek in Mason County, Washington. It was built in 1991, so it is 34 years old, younger than the Washington average of 49.8 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 827 vehicles a day, roughly 5% of them trucks, projected to reach 1,500 by 2040. The structure is 58 ft (17.8 m) long and 30 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

CarriesMission Creek RD
CrossesMission Creek
Location0.40 N JCT SR 300
RouteCounty Highway 83790
Coordinates47.43833, -122.875
Functional classRural Local

Condition and inspection

Good

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
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 rating33 US tons
Inventory rating25 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length58 ft (17.8 m)
Longest span56 ft (17.1 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic827 (2020)
Projected traffic1,500 by 2040
Trucks5%
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

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$80,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Mission Creek RD over Mission Creek built?

It was built in 1991, making it 34 years old in 2025.

What condition is Mission Creek RD over Mission Creek 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 June 2024.

How much traffic does Mission Creek RD over Mission Creek carry?

About 827 vehicles per day (2020 count), of which roughly 5% are trucks.

How long is Mission Creek RD over Mission Creek?

The structure is 58 ft (17.8 m) long with a longest span of 56 ft (17.1 m) and a deck 30 ft wide.

Who owns Mission Creek RD over Mission Creek?

It is owned by the County Highway Agency.