US Bridges

15th LN NW over Teton Canal 030

Fair

Teton County, Montana · 4M N Bynum · Structure no. L50055003+09001

Built
1984
41 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
26 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

15th LN NW over Teton Canal 030 is a wood or timber stringer/multi-beam or girder carrying 15th LN NW over Teton Canal 030 in Teton County, Montana. It was built in 1984, so it is 41 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 26 ft (7.9 m) long and 20 ft wide. If it were closed, the detour would be 13 mi (21 km).

Carries15th LN NW
CrossesTeton Canal 030
Location4M N Bynum
RouteCounty Highway 50055
StateMontana
Coordinates48.03392, -112.30832
Functional classRural Local

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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than 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 alignment7: Better than present minimum criteria
Operating rating55 US tons
Inventory rating40 US tons

Structure

MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length26 ft (7.9 m)
Longest span24 ft (7.3 m)
Deck width20 ft (6.2 m)
Roadway width20 ft (6.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2025)
Projected traffic100 by 2040
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed13 mi (21 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 15th LN NW over Teton Canal 030 built?

It was built in 1984, making it 41 years old in 2025.

What condition is 15th LN NW over Teton Canal 030 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 November 2023.

How much traffic does 15th LN NW over Teton Canal 030 carry?

About 100 vehicles per day (2025 count), of which roughly 3% are trucks.

How long is 15th LN NW over Teton Canal 030?

The structure is 26 ft (7.9 m) long with a longest span of 24 ft (7.3 m) and a deck 20 ft wide.

Who owns 15th LN NW over Teton Canal 030?

It is owned by the County Highway Agency.