US Bridges

Silver Butte RD over Fisher River 075

GoodPosted for load

Lincoln County, Montana · 18M SE Libby · Structure no. L27311000+01001

Built
1938
87 years old
Condition
Good
inspected October 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
67 ft
3 main spans
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Silver Butte RD over Fisher River 075 is a wood or timber stringer/multi-beam or girder carrying Silver Butte RD over Fisher River 075 in Lincoln County, Montana. It was built in 1938, so it is 87 years old, older 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. 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 67 ft (20.4 m) long and 18 ft wide. If it were closed, the detour would be 60.3 mi (97 km).

CarriesSilver Butte RD
CrossesFisher River 075
Location18M SE Libby
RouteCounty Highway 27403
StateMontana
Coordinates48.02506, -115.34939
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
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 rating41 US tons
Inventory rating29 US tons

Structure

MaterialWood or Timber
DeckWood or timber
Main spans3
Design loadUnknown
Structure length67 ft (20.4 m)
Longest span27 ft (8.2 m)
Deck width18 ft (5.5 m)
Roadway width16 ft (4.9 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 closed60.3 mi (97 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$108,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Silver Butte RD over Fisher River 075 built?

It was built in 1938, making it 87 years old in 2025.

What condition is Silver Butte RD over Fisher River 075 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 October 2024.

How much traffic does Silver Butte RD over Fisher River 075 carry?

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

How long is Silver Butte RD over Fisher River 075?

The structure is 67 ft (20.4 m) long with a longest span of 27 ft (8.2 m) and a deck 18 ft wide.

Who owns Silver Butte RD over Fisher River 075?

It is owned by the County Highway Agency.