US Bridges

Sweetwater Road over Drainage

FairPosted for load

Beaverhead County, Montana · 2.6M E Dillon · Structure no. 000000202408089

Built
1980
45 years old
Condition
Fair
inspected March 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
25 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Sweetwater Road over Drainage is a steel stringer/multi-beam or girder carrying Sweetwater Road over Drainage in Beaverhead County, Montana. It was built in 1980, so it is 45 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. Its operating status is: posted for load restriction.

It carries about 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 25 ft (7.7 m) long and 19 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

Open in Google Maps
CarriesSweetwater Road
CrossesDrainage
Location2.6M E Dillon
RouteCounty Highway 1206
CountyBeaverhead County
StateMontana
Coordinates45.21817, -112.56524
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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourScour evaluation has not been made
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating5 US tons
Inventory rating5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length25 ft (7.7 m)
Longest span22 ft (6.8 m)
Deck width19 ft (5.7 m)
Roadway width17 ft (5.3 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 closed9.9 mi (16 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 Sweetwater Road over Drainage built?

It was built in 1980, making it 45 years old in 2025.

What condition is Sweetwater Road over Drainage 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 2024.

How much traffic does Sweetwater Road over Drainage carry?

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

How long is Sweetwater Road over Drainage?

The structure is 25 ft (7.7 m) long with a longest span of 22 ft (6.8 m) and a deck 19 ft wide.

Who owns Sweetwater Road over Drainage?

It is owned by the County Highway Agency.