US Bridges

S 200 over Clark Fork River

Poor

Sanders County, Montana · 1M W Thompson Falls · Structure no. P00006049+03411

Built
1960
65 years old
Condition
Poor
inspected August 2023
Type
Girder and Floorbeam System
Steel Continuous
Length
952 ft
4 main spans
Daily traffic
2,482
2023 count
Owner
State
State Highway Agency

About this bridge

S 200 over Clark Fork River is a steel continuous girder and floorbeam system carrying S 200 over Clark Fork River in Sanders County, Montana. It was built in 1960, so it is 65 years old, older than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 2,482 vehicles a day, roughly 3% of them trucks, projected to reach 2,606 by 2043. The structure is 952 ft (290.3 m) long and 32 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesS 200
CrossesClark Fork River
Location1M W Thompson Falls
RouteState Highway 200
CountySanders County
StateMontana
Coordinates47.60462, -115.37467
Functional classRural Minor Arterial

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52 US tons
Inventory rating32 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4 (+3 approach)
Design loadHS 20
Structure length952 ft (290.3 m)
Longest span200 ft (60.9 m)
Deck width32 ft (9.7 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,482 (2023)
Projected traffic2,606 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 S 200 over Clark Fork River built?

It was built in 1960, making it 65 years old in 2025.

What condition is S 200 over Clark Fork River in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2023.

How much traffic does S 200 over Clark Fork River carry?

About 2,482 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is S 200 over Clark Fork River?

The structure is 952 ft (290.3 m) long with a longest span of 200 ft (60.9 m) and a deck 32 ft wide.

Who owns S 200 over Clark Fork River?

It is owned by the State Highway Agency.