US Bridges

IRR - S 13 over Chelsea Creek

Fair

Roosevelt County, Montana · 18M NE Wolf Point · Structure no. P00032015+03221

Built
1992
33 years old
Condition
Fair
inspected August 2024
Type
Culvert
Steel
Length
27 ft
2 main spans
Daily traffic
368
2023 count
Owner
State
State Highway Agency

About this bridge

IRR - S 13 over Chelsea Creek is a steel culvert carrying IRR - S 13 over Chelsea Creek in Roosevelt County, Montana. It was built in 1992, so it is 33 years old, younger than the Montana average of 47 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 368 vehicles a day, roughly 7% of them trucks, projected to reach 386 by 2043. The structure is 27 ft (8.2 m) long. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesIRR - S 13
CrossesChelsea Creek
Location18M NE Wolf Point
RouteState Highway 13
CountyRoosevelt County
StateMontana
Coordinates48.28227, -105.47367
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating110.1 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans2
Design loadHS 20
Structure length27 ft (8.2 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic368 (2023)
Projected traffic386 by 2043
Trucks7%
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 IRR - S 13 over Chelsea Creek built?

It was built in 1992, making it 33 years old in 2025.

What condition is IRR - S 13 over Chelsea 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 August 2024.

How much traffic does IRR - S 13 over Chelsea Creek carry?

About 368 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is IRR - S 13 over Chelsea Creek?

The structure is 27 ft (8.2 m) long with a longest span of 10 ft (3 m).

Who owns IRR - S 13 over Chelsea Creek?

It is owned by the State Highway Agency.