US Bridges

Tomahawk Road over Island River

Fair

Lake County, Minnesota · 17.1 MI Ene of JCT TH 1 · Structure no. 090907000001028

Built
1985
40 years old
Condition
Fair
inspected September 2023
Type
Girder and Floorbeam System
Wood or Timber
Length
109 ft
7 main spans
Daily traffic
3
1988 count
Owner
Federal
U.S. Forest Service

About this bridge

Tomahawk Road over Island River is a wood or timber girder and floorbeam system carrying Tomahawk Road over Island River in Lake County, Minnesota. It was built in 1985, so it is 40 years old, older than the Minnesota average of 38.5 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 3 vehicles a day, projected to reach 4 by 2045. The structure is 109 ft (33.2 m) long and 16 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

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CarriesTomahawk Road
CrossesIsland River
Location17.1 MI Ene of JCT TH 1
RouteFederal Lands Road 377
CountyLake County
StateMinnesota
Coordinates47.79444, -91.31944
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30.3 US tons
Inventory rating23.6 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialWood or Timber
DeckWood or timber
Main spans7
Design loadHS 20
Structure length109 ft (33.2 m)
Longest span17 ft (5.2 m)
Deck width16 ft (4.9 m)
Roadway width15 ft (4.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3 (1988)
Projected traffic4 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 Tomahawk Road over Island River built?

It was built in 1985, making it 40 years old in 2025.

What condition is Tomahawk Road over Island 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 September 2023.

How much traffic does Tomahawk Road over Island River carry?

About 3 vehicles per day (1988 count).

How long is Tomahawk Road over Island River?

The structure is 109 ft (33.2 m) long with a longest span of 17 ft (5.2 m) and a deck 16 ft wide.

Who owns Tomahawk Road over Island River?

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