US Bridges

Augusta RD over Dearborn River 011

FairPosted for load

Lewis and Clark County, Montana · 18M S Augusta · Structure no. L25300009+00001

Built
1896
129 years old, rebuilt 2003
Condition
Fair
inspected July 2024
Type
Truss - Thru
Steel
Length
251 ft
1 main span
Daily traffic
31
2023 count
Owner
County
County Highway Agency

About this bridge

Augusta RD over Dearborn River 011 is a steel truss - thru carrying Augusta RD over Dearborn River 011 in Lewis and Clark County, Montana. It was built in 1896 and reconstructed in 2003, so it is 129 years old, older 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. Its operating status is: posted for load restriction.

It carries about 31 vehicles a day, roughly 3% of them trucks, projected to reach 33 by 2043. The structure is 251 ft (76.5 m) long and 16 ft wide. If it were closed, the detour would be 29.8 mi (48 km).

Location

Open in Google Maps
CarriesAugusta RD
CrossesDearborn River 011
Location18M S Augusta
RouteCounty Highway 25300
CountyLewis and Clark County
StateMontana
Coordinates47.28116, -112.39111
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating7.7 US tons
Inventory rating4.6 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckWood or timber
Main spans1 (+3 approach)
Design loadUnknown
Structure length251 ft (76.5 m)
Longest span160 ft (48.8 m)
Deck width16 ft (4.9 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic31 (2023)
Projected traffic33 by 2043
Trucks3%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusListed on the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Augusta RD over Dearborn River 011 built?

It was built in 1896, making it 129 years old in 2025. It was reconstructed in 2003.

What condition is Augusta RD over Dearborn River 011 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 July 2024.

How much traffic does Augusta RD over Dearborn River 011 carry?

About 31 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Augusta RD over Dearborn River 011?

The structure is 251 ft (76.5 m) long with a longest span of 160 ft (48.8 m) and a deck 16 ft wide.

Who owns Augusta RD over Dearborn River 011?

It is owned by the County Highway Agency.