US Bridges

S 221 over Teton River

Fair

Teton County, Montana · 5M E Choteau · Structure no. S00221004+09001

Built
1939
86 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
270 ft
3 main spans
Daily traffic
183
2023 count
Owner
State
State Highway Agency

About this bridge

S 221 over Teton River is a steel continuous stringer/multi-beam or girder carrying S 221 over Teton River in Teton County, Montana. It was built in 1939, so it is 86 years old, older 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 5 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 183 vehicles a day, roughly 22% of them trucks, projected to reach 192 by 2043. The structure is 270 ft (82.3 m) long and 28 ft wide. If it were closed, the detour would be 78.3 mi (126 km).

Location

Open in Google Maps
CarriesS 221
CrossesTeton River
Location5M E Choteau
RouteState Highway 221
CountyTeton County
StateMontana
Coordinates47.81323, -112.07924
Functional classRural Major 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 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 rating49.1 US tons
Inventory rating29 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+3 approach)
Design loadH 15
Structure length270 ft (82.3 m)
Longest span65 ft (19.8 m)
Deck width28 ft (8.5 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic183 (2023)
Projected traffic192 by 2043
Trucks22%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed78.3 mi (126 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 221 over Teton River built?

It was built in 1939, making it 86 years old in 2025.

What condition is S 221 over Teton 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 October 2024.

How much traffic does S 221 over Teton River carry?

About 183 vehicles per day (2023 count), of which roughly 22% are trucks.

How long is S 221 over Teton River?

The structure is 270 ft (82.3 m) long with a longest span of 65 ft (19.8 m) and a deck 28 ft wide.

Who owns S 221 over Teton River?

It is owned by the State Highway Agency.