US Bridges

M-69 over Michigamme River

Poor

Iron County, Michigan · 5.8 MI E of Crystal Falls · Structure no. 000000000004173

Built
1931
94 years old
Condition
Poor
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
150 ft
3 main spans
Daily traffic
1,571
2007 count
Owner
State
State Highway Agency

About this bridge

M-69 over Michigamme River is a steel stringer/multi-beam or girder carrying M-69 over Michigamme River in Iron County, Michigan. It was built in 1931, so it is 94 years old, older than the Michigan average of 48.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 1,571 vehicles a day, roughly 17% of them trucks, projected to reach 2,067 by 2018. The structure is 150 ft (45.7 m) long and 38 ft wide. If it were closed, the detour would be 62.1 mi (100 km).

Location

Open in Google Maps
CarriesM-69
CrossesMichigamme River
Location5.8 MI E of Crystal Falls
RouteState Highway 69
CountyIron County
StateMichigan
Coordinates46.08363, -88.22286
Functional classRural Minor Arterial

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating67.1 US tons
Inventory rating40 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadH 15
Structure length150 ft (45.7 m)
Longest span49 ft (14.8 m)
Deck width38 ft (11.7 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,571 (2007)
Projected traffic2,067 by 2018
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed62.1 mi (100 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 proposedDeck replacement with only incidental widening
Estimated improvement cost$144,000
NavigationNo navigation control on waterway

Frequently asked questions

When was M-69 over Michigamme River built?

It was built in 1931, making it 94 years old in 2025.

What condition is M-69 over Michigamme River in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in September 2024.

How much traffic does M-69 over Michigamme River carry?

About 1,571 vehicles per day (2007 count), of which roughly 17% are trucks.

How long is M-69 over Michigamme River?

The structure is 150 ft (45.7 m) long with a longest span of 49 ft (14.8 m) and a deck 38 ft wide.

Who owns M-69 over Michigamme River?

It is owned by the State Highway Agency.