US Bridges

Galena Gulch Road over Boulder River

Fair

Jefferson County, Montana · I15 High Ore Exit · Structure no. 010902000000036

Built
1957
68 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
72 ft
2 main spans
Daily traffic
50
Owner
Federal
U.S. Forest Service

About this bridge

Galena Gulch Road over Boulder River is a wood or timber stringer/multi-beam or girder carrying Galena Gulch Road over Boulder River in Jefferson County, Montana. It was built in 1957, so it is 68 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 72 ft (21.8 m) long and 15 ft wide. If it were closed, the detour would be 14.9 mi (24 km).

Location

Open in Google Maps
CarriesGalena Gulch Road
CrossesBoulder River
LocationI15 High Ore Exit
RouteFederal Lands Road 638
CountyJefferson County
StateMontana
Coordinates46.25399, -112.1829
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating33.2 US tons
Inventory rating25.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans2
Design loadHS 25 or greater
Structure length72 ft (21.8 m)
Longest span35 ft (10.7 m)
Deck width15 ft (4.7 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (—)
Projected traffic75 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed14.9 mi (24 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Galena Gulch Road over Boulder River built?

It was built in 1957, making it 68 years old in 2025.

What condition is Galena Gulch Road over Boulder 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 September 2024.

How much traffic does Galena Gulch Road over Boulder River carry?

About 50 vehicles per day (latest count).

How long is Galena Gulch Road over Boulder River?

The structure is 72 ft (21.8 m) long with a longest span of 35 ft (10.7 m) and a deck 15 ft wide.

Who owns Galena Gulch Road over Boulder River?

It is owned by the U.S. Forest Service.