US Bridges

Lil Bitterroot RD over Little Bitterroot 074

Fair

Sanders County, Montana · 12M W Ronan · Structure no. L45225006+07001

Built
1986
39 years old
Condition
Fair
inspected March 2023
Type
Tee Beam
Prestressed Concrete
Length
82 ft
1 main span
Daily traffic
100
2025 count
Owner
County
County Highway Agency

About this bridge

Lil Bitterroot RD over Little Bitterroot 074 is a prestressed concrete tee beam carrying Lil Bitterroot RD over Little Bitterroot 074 in Sanders County, Montana. It was built in 1986, so it is 39 years old, younger 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 100 vehicles a day, roughly 3% of them trucks, projected to reach 100 by 2040. The structure is 82 ft (25 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesLil Bitterroot RD
CrossesLittle Bitterroot 074
Location12M W Ronan
RouteCounty Highway 45305
StateMontana
Coordinates47.49266, -114.32973
Functional classRural Major Collector

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 protection8 Very GoodNo problems noted.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating51 US tons
Inventory rating31 US tons

Structure

Structure typeTee Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length82 ft (25 m)
Longest span80 ft (24.4 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.5 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 closed123.7 mi (199 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 Lil Bitterroot RD over Little Bitterroot 074 built?

It was built in 1986, making it 39 years old in 2025.

What condition is Lil Bitterroot RD over Little Bitterroot 074 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 March 2023.

How much traffic does Lil Bitterroot RD over Little Bitterroot 074 carry?

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

How long is Lil Bitterroot RD over Little Bitterroot 074?

The structure is 82 ft (25 m) long with a longest span of 80 ft (24.4 m) and a deck 31 ft wide.

Who owns Lil Bitterroot RD over Little Bitterroot 074?

It is owned by the County Highway Agency.