US Bridges

Csah 100 over ST Louis River

Fair

St. Louis County, Minnesota · 1.7 MI S of JCT CSAH110 · Structure no. 7183

Built
1958
67 years old
Condition
Fair
inspected July 2024
Type
Girder and Floorbeam System
Concrete Continuous
Length
168 ft
3 main spans
Daily traffic
1,450
2019 count
Owner
County
County Highway Agency

About this bridge

Csah 100 over ST Louis River is a concrete continuous girder and floorbeam system carrying Csah 100 over ST Louis River in St. Louis County, Minnesota. It was built in 1958, so it is 67 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 1,450 vehicles a day, projected to reach 1,400 by 2039. The structure is 168 ft (51.3 m) long and 32 ft wide. If it were closed, the detour would be 11.2 mi (18 km).

Location

Open in Google Maps
CarriesCsah 100
CrossesST Louis River
Location1.7 MI S of JCT CSAH110
RouteCounty Highway 100
CountySt. Louis County
StateMinnesota
Coordinates47.49257, -92.23835
Functional classRural Major Collector

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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
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
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.2 US tons
Inventory rating34 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length168 ft (51.3 m)
Longest span63 ft (19.2 m)
Deck width32 ft (9.9 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,450 (2019)
Projected traffic1,400 by 2039
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.2 mi (18 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$759 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Csah 100 over ST Louis River built?

It was built in 1958, making it 67 years old in 2025.

What condition is Csah 100 over ST Louis 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 July 2024.

How much traffic does Csah 100 over ST Louis River carry?

About 1,450 vehicles per day (2019 count).

How long is Csah 100 over ST Louis River?

The structure is 168 ft (51.3 m) long with a longest span of 63 ft (19.2 m) and a deck 32 ft wide.

Who owns Csah 100 over ST Louis River?

It is owned by the County Highway Agency.