US Bridges

Lower N Fork RD over Irrigation Canal 068

Fair

Beaverhead County, Montana · 7M N Wisdom · Structure no. L01003006+06001

Built
1994
31 years old
Condition
Fair
inspected October 2024
Type
Channel Beam
Prestressed Concrete
Length
29 ft
1 main span
Daily traffic
35
2023 count
Owner
County
County Highway Agency

About this bridge

Lower N Fork RD over Irrigation Canal 068 is a prestressed concrete channel beam carrying Lower N Fork RD over Irrigation Canal 068 in Beaverhead County, Montana. It was built in 1994, so it is 31 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 35 vehicles a day, roughly 3% of them trucks, projected to reach 37 by 2043. The structure is 29 ft (8.8 m) long and 24 ft wide. If it were closed, the detour would be 16.8 mi (27 km).

CarriesLower N Fork RD
CrossesIrrigation Canal 068
Location7M N Wisdom
RouteCounty Highway 1003
StateMontana
Coordinates45.71455, -113.45877
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating36 US tons
Inventory rating36 US tons

Structure

Structure typeChannel Beam
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHS 20
Structure length29 ft (8.8 m)
Longest span29 ft (8.8 m)
Deck width24 ft (7.3 m)
Roadway width23 ft (7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2023)
Projected traffic37 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.8 mi (27 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 Lower N Fork RD over Irrigation Canal 068 built?

It was built in 1994, making it 31 years old in 2025.

What condition is Lower N Fork RD over Irrigation Canal 068 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 2024.

How much traffic does Lower N Fork RD over Irrigation Canal 068 carry?

About 35 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Lower N Fork RD over Irrigation Canal 068?

The structure is 29 ft (8.8 m) long with a longest span of 29 ft (8.8 m) and a deck 24 ft wide.

Who owns Lower N Fork RD over Irrigation Canal 068?

It is owned by the County Highway Agency.