US Bridges

Hogum Ck Road over Blackfoot River

Fair

Lewis and Clark County, Montana · Hogum-Blackfoot · Structure no. 011204000000041

Built
1965
60 years old
Condition
Fair
inspected October 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
47 ft
1 main span
Daily traffic
46
1986 count
Owner
Federal
U.S. Forest Service

About this bridge

Hogum Ck Road over Blackfoot River is a wood or timber stringer/multi-beam or girder carrying Hogum Ck Road over Blackfoot River in Lewis and Clark County, Montana. It was built in 1965, so it is 60 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 46 vehicles a day, projected to reach 69 by 2045. The structure is 47 ft (14.2 m) long and 15 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
CarriesHogum Ck Road
CrossesBlackfoot River
LocationHogum-Blackfoot
RouteFederal Lands Road 1841
CountyLewis and Clark County
StateMontana
Coordinates46.9892, -112.51204
Functional classRural Local

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating26.8 US tons
Inventory rating20.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadUnknown
Structure length47 ft (14.2 m)
Longest span45 ft (13.7 m)
Deck width15 ft (4.7 m)
Roadway width14 ft (4.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic46 (1986)
Projected traffic69 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Hogum Ck Road over Blackfoot River built?

It was built in 1965, making it 60 years old in 2025.

What condition is Hogum Ck Road over Blackfoot 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 Hogum Ck Road over Blackfoot River carry?

About 46 vehicles per day (1986 count).

How long is Hogum Ck Road over Blackfoot River?

The structure is 47 ft (14.2 m) long with a longest span of 45 ft (13.7 m) and a deck 15 ft wide.

Who owns Hogum Ck Road over Blackfoot River?

It is owned by the U.S. Forest Service.