US Bridges

CR 406 over Willow River

Good

St. Louis County, Minnesota · 0.5 MI S of JCT CSAH74 · Structure no. 69K30

Built
2015
10 years old
Condition
Good
inspected August 2023
Type
Culvert
Concrete
Length
31 ft
2 main spans
Daily traffic
35
2019 count
Owner
County
County Highway Agency

About this bridge

CR 406 over Willow River is a concrete culvert carrying CR 406 over Willow River in St. Louis County, Minnesota. It was built in 2015, so it is 10 years old, younger than the Minnesota average of 38.5 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 35 vehicles a day, projected to reach 114 by 2039. The structure is 31 ft (9.5 m) long. If it were closed, the detour would be 8.1 mi (13 km).

CarriesCR 406
CrossesWillow River
Location0.5 MI S of JCT CSAH74
RouteCounty Highway 406
Coordinates47.95688, -92.87212
Functional classRural Local

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Channel and channel protection7 GoodSome minor problems.
Culvert8 Very GoodNo problems noted.
Last inspectionAugust 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46.4 US tons
Inventory rating35.7 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans2
Design loadHL 93
Structure length31 ft (9.5 m)
Longest span14 ft (4.3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2019)
Projected traffic114 by 2039
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 CR 406 over Willow River built?

It was built in 2015, making it 10 years old in 2025.

What condition is CR 406 over Willow River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in August 2023.

How much traffic does CR 406 over Willow River carry?

About 35 vehicles per day (2019 count).

How long is CR 406 over Willow River?

The structure is 31 ft (9.5 m) long with a longest span of 14 ft (4.3 m).

Who owns CR 406 over Willow River?

It is owned by the County Highway Agency.