US Bridges

M 712 over Amity Creek

Fair

St. Louis County, Minnesota · 1.5 MI N of JCT CSAH12 · Structure no. L8506

Built
1912
113 years old
Condition
Fair
inspected October 2023
Type
Arch - Deck
Concrete
Length
62 ft
2 main spans
Daily traffic
130
2003 count
Owner
City
City or Municipal Highway Agency

About this bridge

M 712 over Amity Creek is a concrete arch - deck carrying M 712 over Amity Creek in St. Louis County, Minnesota. It was built in 1912, so it is 113 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 130 vehicles a day, projected to reach 130 by 2029. The structure is 62 ft (18.9 m) long and 22 ft wide. If it were closed, the detour would be 6.8 mi (11 km).

Location

Open in Google Maps
CarriesM 712
CrossesAmity Creek
Location1.5 MI N of JCT CSAH12
RouteCity Street 712
CountySt. Louis County
StateMinnesota
Coordinates46.85943, -92.014
Functional classUrban 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
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating54 US tons
Inventory rating36 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans2
Design loadUnknown
Structure length62 ft (18.9 m)
Longest span28 ft (8.5 m)
Deck width22 ft (6.7 m)
Roadway width19 ft (5.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic130 (2003)
Projected traffic130 by 2029
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.8 mi (11 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was M 712 over Amity Creek built?

It was built in 1912, making it 113 years old in 2025.

What condition is M 712 over Amity Creek 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 October 2023.

How much traffic does M 712 over Amity Creek carry?

About 130 vehicles per day (2003 count).

How long is M 712 over Amity Creek?

The structure is 62 ft (18.9 m) long with a longest span of 28 ft (8.5 m) and a deck 22 ft wide.

Who owns M 712 over Amity Creek?

It is owned by the City or Municipal Highway Agency.