US Bridges

Spire Rock Cg Loop over Stormcastle Creek

Fair

Gallatin County, Montana · Spire Rock Campground · Structure no. 011106000000060

Built
1957
68 years old
Condition
Fair
inspected September 2021
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
32 ft
1 main span
Daily traffic
50
1993 count
Owner
Federal
U.S. Forest Service

About this bridge

Spire Rock Cg Loop over Stormcastle Creek is a wood or timber stringer/multi-beam or girder carrying Spire Rock Cg Loop over Stormcastle Creek in Gallatin 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 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 50 vehicles a day, projected to reach 75 by 2045. The structure is 32 ft (9.9 m) long and 15 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
CarriesSpire Rock Cg Loop
CrossesStormcastle Creek
LocationSpire Rock Campground
RouteFederal Lands Road 132
CountyGallatin County
StateMontana
Coordinates45.44055, -111.19006
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.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2021
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating32.8 US tons
Inventory rating25.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadHS 20
Structure length32 ft (9.9 m)
Longest span31 ft (9.4 m)
Deck width15 ft (4.7 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (1993)
Projected traffic75 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 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 Spire Rock Cg Loop over Stormcastle Creek built?

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

What condition is Spire Rock Cg Loop over Stormcastle 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 September 2021.

How much traffic does Spire Rock Cg Loop over Stormcastle Creek carry?

About 50 vehicles per day (1993 count).

How long is Spire Rock Cg Loop over Stormcastle Creek?

The structure is 32 ft (9.9 m) long with a longest span of 31 ft (9.4 m) and a deck 15 ft wide.

Who owns Spire Rock Cg Loop over Stormcastle Creek?

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