US Bridges

Mn 73 over East Branch Sturgeon R

Fair

St. Louis County, Minnesota · 11.6 MI N of N JCT TH169 · Structure no. 5889

Built
1940
85 years old
Condition
Fair
inspected June 2023
Type
Culvert
Concrete
Length
40 ft
3 main spans
Daily traffic
556
2022 count
Owner
State
State Highway Agency

About this bridge

Mn 73 over East Branch Sturgeon R is a concrete culvert carrying Mn 73 over East Branch Sturgeon R in St. Louis County, Minnesota. It was built in 1940, so it is 85 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 6 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 556 vehicles a day, roughly 16% of them trucks, projected to reach 680 by 2042. The structure is 40 ft (12.2 m) long. If it were closed, the detour would be 29.8 mi (48 km).

Location

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CarriesMn 73
CrossesEast Branch Sturgeon R
Location11.6 MI N of N JCT TH169
RouteState Highway 73
CountySt. Louis County
StateMinnesota
Coordinates47.63294, -92.86478
Functional classRural Minor Arterial

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 protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating43.2 US tons
Inventory rating32.4 US tons

Structure

Structure typeCulvert
MaterialConcrete
DeckNot applicable
Main spans3
Design loadUnknown
Structure length40 ft (12.2 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 traffic556 (2022)
Projected traffic680 by 2042
Trucks16%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed29.8 mi (48 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost$130 million
NavigationNo navigation control on waterway

Frequently asked questions

When was Mn 73 over East Branch Sturgeon R built?

It was built in 1940, making it 85 years old in 2025.

What condition is Mn 73 over East Branch Sturgeon R 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 June 2023.

How much traffic does Mn 73 over East Branch Sturgeon R carry?

About 556 vehicles per day (2022 count), of which roughly 16% are trucks.

How long is Mn 73 over East Branch Sturgeon R?

The structure is 40 ft (12.2 m) long with a longest span of 14 ft (4.3 m).

Who owns Mn 73 over East Branch Sturgeon R?

It is owned by the State Highway Agency.