US Bridges

Forest Road over North Fork Lost Creek

Good

Lake County, Montana · South Lost · Structure no. 011001000016329

Built
2014
11 years old
Condition
Good
inspected July 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
60 ft
1 main span
Daily traffic
40
Owner
Federal
U.S. Forest Service

About this bridge

Forest Road over North Fork Lost Creek is a prestressed concrete stringer/multi-beam or girder carrying Forest Road over North Fork Lost Creek in Lake County, Montana. It was built in 2014, so it is 11 years old, younger than the Montana average of 47 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 40 vehicles a day, projected to reach 60 by 2045. The structure is 60 ft (18.3 m) long and 16 ft wide. If it were closed, the detour would be 620.7 mi (999 km).

CarriesForest Road
CrossesNorth Fork Lost Creek
LocationSouth Lost
RouteFederal Lands Road 680
StateMontana
Coordinates47.88494, -113.79885
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating42.9 US tons
Inventory rating33.2 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length60 ft (18.3 m)
Longest span57 ft (17.4 m)
Deck width16 ft (4.9 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40 (—)
Projected traffic60 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed620.7 mi (999 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 Forest Road over North Fork Lost Creek built?

It was built in 2014, making it 11 years old in 2025.

What condition is Forest Road over North Fork Lost Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2024.

How much traffic does Forest Road over North Fork Lost Creek carry?

About 40 vehicles per day (latest count).

How long is Forest Road over North Fork Lost Creek?

The structure is 60 ft (18.3 m) long with a longest span of 57 ft (17.4 m) and a deck 16 ft wide.

Who owns Forest Road over North Fork Lost Creek?

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