US Bridges

US 12 FH 11 over Lolo Creek

Fair

Missoula County, Montana · Lolo Hot Springs · Structure no. P00093007+04881

Built
1957
68 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
64 ft
3 main spans
Daily traffic
799
2023 count
Owner
State
State Highway Agency

About this bridge

US 12 FH 11 over Lolo Creek is a wood or timber stringer/multi-beam or girder carrying US 12 FH 11 over Lolo Creek in Missoula 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 799 vehicles a day, roughly 7% of them trucks, projected to reach 839 by 2043. The structure is 64 ft (19.5 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesUS 12 FH 11
CrossesLolo Creek
LocationLolo Hot Springs
RouteU.S. Route 12
CountyMissoula County
StateMontana
Coordinates46.72757, -114.53096
Functional classRural Principal Arterial - Other

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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating47 US tons
Inventory rating32 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans3
Design loadHS 20
Structure length64 ft (19.5 m)
Longest span21 ft (6.4 m)
Deck width31 ft (9.5 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic799 (2023)
Projected traffic839 by 2043
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemYes

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 US 12 FH 11 over Lolo Creek built?

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

What condition is US 12 FH 11 over Lolo 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 August 2024.

How much traffic does US 12 FH 11 over Lolo Creek carry?

About 799 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is US 12 FH 11 over Lolo Creek?

The structure is 64 ft (19.5 m) long with a longest span of 21 ft (6.4 m) and a deck 31 ft wide.

Who owns US 12 FH 11 over Lolo Creek?

It is owned by the State Highway Agency.