US Bridges

County Highway over Cottonwood Lake

PoorPosted for load

Mountrail County, North Dakota · 6 North 1 East Manitou · Structure no. 000000031114080

Built
1946
79 years old
Condition
Poor
inspected June 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
86 ft
2 main spans
Daily traffic
20
2018 count
Owner
County
County Highway Agency

About this bridge

County Highway over Cottonwood Lake is a steel stringer/multi-beam or girder carrying County Highway over Cottonwood Lake in Mountrail County, North Dakota. It was built in 1946, so it is 79 years old, older than the North Dakota average of 48.2 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 20 vehicles a day, projected to reach 20 by 2038. The structure is 86 ft (26.2 m) long and 22 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesCounty Highway
CrossesCottonwood Lake
Location6 North 1 East Manitou
RouteCounty Highway 0
CountyMountrail County
StateNorth Dakota
Coordinates48.43469, -102.59926
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment6: Equal to present minimum criteria
Operating rating20 US tons
Inventory rating11.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadH 15
Structure length86 ft (26.2 m)
Longest span41 ft (12.5 m)
Deck width22 ft (6.6 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic20 (2018)
Projected traffic20 by 2038
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$270,000
NavigationNo navigation control on waterway

Frequently asked questions

When was County Highway over Cottonwood Lake built?

It was built in 1946, making it 79 years old in 2025.

What condition is County Highway over Cottonwood Lake in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in June 2024.

How much traffic does County Highway over Cottonwood Lake carry?

About 20 vehicles per day (2018 count).

How long is County Highway over Cottonwood Lake?

The structure is 86 ft (26.2 m) long with a longest span of 41 ft (12.5 m) and a deck 22 ft wide.

Who owns County Highway over Cottonwood Lake?

It is owned by the County Highway Agency.