US Bridges

Modrow RD over Kalama River

FairPosted for load

Cowlitz County, Washington · 0.01 S Kal Riv RD (1.23) · Structure no. 084286000000000

Built
1958
67 years old
Condition
Fair
inspected March 2023
Type
Arch - Deck
Steel
Length
200 ft
1 main span
Daily traffic
795
2015 count
Owner
County
County Highway Agency

About this bridge

Modrow RD over Kalama River is a steel arch - deck carrying Modrow RD over Kalama River in Cowlitz County, Washington. It was built in 1958, so it is 67 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. Its operating status is: posted for load restriction.

It carries about 795 vehicles a day, roughly 9% of them trucks, projected to reach 960 by 2032. The structure is 200 ft (61 m) long and 29 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

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CarriesModrow RD
CrossesKalama River
Location0.01 S Kal Riv RD (1.23)
RouteCounty Highway 35350
CountyCowlitz County
StateWashington
Coordinates46.04722, -122.8375
Functional classRural Minor 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being 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 rating34 US tons
Inventory rating20 US tons

Structure

Structure typeArch - Deck
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+5 approach)
Design loadHS 15
Structure length200 ft (61 m)
Longest span120 ft (36.6 m)
Deck width29 ft (8.8 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic795 (2015)
Projected traffic960 by 2032
Trucks9%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Modrow RD over Kalama River built?

It was built in 1958, making it 67 years old in 2025.

What condition is Modrow RD over Kalama River 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 Modrow RD over Kalama River carry?

About 795 vehicles per day (2015 count), of which roughly 9% are trucks.

How long is Modrow RD over Kalama River?

The structure is 200 ft (61 m) long with a longest span of 120 ft (36.6 m) and a deck 29 ft wide.

Who owns Modrow RD over Kalama River?

It is owned by the County Highway Agency.