US Bridges

Tomahawk Road over Little Isabella River

Fair

Lake County, Minnesota · 7.0 MI E of JCT TH 1 · Structure no. 090905000001030

Built
1967
58 years old
Condition
Fair
inspected September 2023
Type
Culvert
Steel
Length
28 ft
2 main spans
Daily traffic
42
1973 count
Owner
Federal
U.S. Forest Service

About this bridge

Tomahawk Road over Little Isabella River is a steel culvert carrying Tomahawk Road over Little Isabella River in Lake County, Minnesota. It was built in 1967, so it is 58 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 5 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 42 vehicles a day, projected to reach 63 by 2045. The structure is 28 ft (8.6 m) long. If it were closed, the detour would be 98.2 mi (158 km).

CarriesTomahawk Road
CrossesLittle Isabella River
Location7.0 MI E of JCT TH 1
RouteFederal Lands Road 377
Coordinates47.73944, -91.50583
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
Channel and channel protection8 Very GoodNo problems noted.
Culvert5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionSeptember 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
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating40 US tons
Inventory rating31.1 US tons

Structure

Structure typeCulvert
MaterialSteel
DeckNot applicable
Main spans2
Design loadUnknown
Structure length28 ft (8.6 m)
Longest span8 ft (2.4 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic42 (1973)
Projected traffic63 by 2045
Trucks—
Lanes on structure2
Traffic directionTwo-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 Little Isabella River built?

It was built in 1967, making it 58 years old in 2025.

What condition is Tomahawk Road over Little Isabella 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 Little Isabella River carry?

About 42 vehicles per day (1973 count).

How long is Tomahawk Road over Little Isabella River?

The structure is 28 ft (8.6 m) long with a longest span of 8 ft (2.4 m).

Who owns Tomahawk Road over Little Isabella River?

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