US Bridges

Wilkes Creek Road over Prospect Creek 006

Good

Sanders County, Montana · 3M SW Thompson Falls · Structure no. L45074000+01001

Built
1978
47 years old
Condition
Good
inspected July 2024
Type
Tee Beam
Prestressed Concrete
Length
74 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Wilkes Creek Road over Prospect Creek 006 is a prestressed concrete tee beam carrying Wilkes Creek Road over Prospect Creek 006 in Sanders County, Montana. It was built in 1978, so it is 47 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 74 ft (22.6 m) long and 20 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

CarriesWilkes Creek Road
CrossesProspect Creek 006
Location3M SW Thompson Falls
RouteCounty Highway 45167
StateMontana
Coordinates47.57583, -115.39378
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 inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52.9 US tons
Inventory rating36 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length74 ft (22.6 m)
Longest span72 ft (21.9 m)
Deck width20 ft (6.1 m)
Roadway width19 ft (5.9 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 closed3.1 mi (5 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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Wilkes Creek Road over Prospect Creek 006 built?

It was built in 1978, making it 47 years old in 2025.

What condition is Wilkes Creek Road over Prospect Creek 006 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 Wilkes Creek Road over Prospect Creek 006 carry?

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

How long is Wilkes Creek Road over Prospect Creek 006?

The structure is 74 ft (22.6 m) long with a longest span of 72 ft (21.9 m) and a deck 20 ft wide.

Who owns Wilkes Creek Road over Prospect Creek 006?

It is owned by the County Highway Agency.