US Bridges

CR 312 over ST Louis River

Good

St. Louis County, Minnesota · 0.6 MI N of JCT Csah 27 · Structure no. 69634

Built
2001
24 years old
Condition
Good
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
243 ft
3 main spans
Daily traffic
50
2019 count
Owner
County
County Highway Agency

About this bridge

CR 312 over ST Louis River is a prestressed concrete stringer/multi-beam or girder carrying CR 312 over ST Louis River in St. Louis County, Minnesota. It was built in 2001, so it is 24 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 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 50 vehicles a day, projected to reach 70 by 2039. The structure is 243 ft (74.2 m) long and 34 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesCR 312
CrossesST Louis River
Location0.6 MI N of JCT Csah 27
RouteCounty Highway 312
CountySt. Louis County
StateMinnesota
Coordinates47.31387, -92.66285
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
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation7: Better than present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating86 US tons
Inventory rating47.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 25 or greater
Structure length243 ft (74.2 m)
Longest span92 ft (28 m)
Deck width34 ft (10.5 m)
Roadway width31 ft (9.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (2019)
Projected traffic70 by 2039
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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 312 over ST Louis River built?

It was built in 2001, making it 24 years old in 2025.

What condition is CR 312 over ST Louis 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 October 2023.

How much traffic does CR 312 over ST Louis River carry?

About 50 vehicles per day (2019 count).

How long is CR 312 over ST Louis River?

The structure is 243 ft (74.2 m) long with a longest span of 92 ft (28 m) and a deck 34 ft wide.

Who owns CR 312 over ST Louis River?

It is owned by the County Highway Agency.