US Bridges

Lake Helena DR over Causeway-Lake Helena 072

Fair

Lewis and Clark County, Montana · 8M N East Helena · Structure no. L25100000+07001

Built
1944
81 years old
Condition
Fair
inspected March 2023
Type
Slab
Concrete
Length
25 ft
2 main spans
Daily traffic
971
2023 count
Owner
County
County Highway Agency

About this bridge

Lake Helena DR over Causeway-Lake Helena 072 is a concrete slab carrying Lake Helena DR over Causeway-Lake Helena 072 in Lewis and Clark County, Montana. It was built in 1944, so it is 81 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.

It carries about 971 vehicles a day, roughly 3% of them trucks, projected to reach 1,039 by 2043. The structure is 25 ft (7.6 m) long and 22 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesLake Helena DR
CrossesCauseway-Lake Helena 072
Location8M N East Helena
RouteCounty Highway 25034
CountyLewis and Clark County
StateMontana
Coordinates46.70215, -111.90109
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.
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 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 alignment6: Equal to present minimum criteria
Operating rating45 US tons
Inventory rating27 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length25 ft (7.6 m)
Longest span11 ft (3.4 m)
Deck width22 ft (6.8 m)
Roadway width20 ft (6.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic971 (2023)
Projected traffic1,039 by 2043
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 Lake Helena DR over Causeway-Lake Helena 072 built?

It was built in 1944, making it 81 years old in 2025.

What condition is Lake Helena DR over Causeway-Lake Helena 072 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 Lake Helena DR over Causeway-Lake Helena 072 carry?

About 971 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Lake Helena DR over Causeway-Lake Helena 072?

The structure is 25 ft (7.6 m) long with a longest span of 11 ft (3.4 m) and a deck 22 ft wide.

Who owns Lake Helena DR over Causeway-Lake Helena 072?

It is owned by the County Highway Agency.