US Bridges

Lima Dam Road over Red Rock River

Fair

Beaverhead County, Montana · 5M E Lima · Structure no. 000000201902165

Built
2019
6 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
38 ft
1 main span
Daily traffic
118
2023 count
Owner
County
County Highway Agency

About this bridge

Lima Dam Road over Red Rock River is a steel stringer/multi-beam or girder carrying Lima Dam Road over Red Rock River in Beaverhead County, Montana. It was built in 2019, so it is 6 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 118 vehicles a day, roughly 3% of them trucks, projected to reach 126 by 2043. The structure is 38 ft (11.5 m) long and 24 ft wide. If it were closed, the detour would be 54.1 mi (87 km).

Location

Open in Google Maps
CarriesLima Dam Road
CrossesRed Rock River
Location5M E Lima
RouteCounty Highway 1205
CountyBeaverhead County
StateMontana
Coordinates44.65467, -112.50326
Functional classRural Minor 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating44 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckCorrugated steel
Main spans1
Design loadHL 93
Structure length38 ft (11.5 m)
Longest span37 ft (11.3 m)
Deck width24 ft (7.4 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic118 (2023)
Projected traffic126 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed54.1 mi (87 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Lima Dam Road over Red Rock River built?

It was built in 2019, making it 6 years old in 2025.

What condition is Lima Dam Road over Red Rock River 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 October 2023.

How much traffic does Lima Dam Road over Red Rock River carry?

About 118 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Lima Dam Road over Red Rock River?

The structure is 38 ft (11.5 m) long with a longest span of 37 ft (11.3 m) and a deck 24 ft wide.

Who owns Lima Dam Road over Red Rock River?

It is owned by the County Highway Agency.