US Bridges

Miners Castle Road over Miners River

Fair

Alger County, Michigan · 0.5 Miles North of Miners · Structure no. 6320001P0000000

Built
1953
72 years old
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
20 ft
1 main span
Daily traffic
150
2019 count
Owner
Federal
National Park Service

About this bridge

Miners Castle Road over Miners River is a steel stringer/multi-beam or girder carrying Miners Castle Road over Miners River in Alger County, Michigan. It was built in 1953, so it is 72 years old, older than the Michigan average of 48.3 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 150 vehicles a day, roughly 1% of them trucks, projected to reach 165 by 2039. The structure is 20 ft (6.1 m) long and 30 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesMiners Castle Road
CrossesMiners River
Location0.5 Miles North of Miners
RouteFederal Lands Road 12
CountyAlger County
StateMichigan
Coordinates46.48836, -86.54061
Functional classRural Minor 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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
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 inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.9 US tons
Inventory rating37 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadUnknown
Structure length20 ft (6.1 m)
Longest span20 ft (6.1 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic150 (2019)
Projected traffic165 by 2039
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerNational Park Service
Maintained byNational Park Service
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost$7 million (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Miners Castle Road over Miners River built?

It was built in 1953, making it 72 years old in 2025.

What condition is Miners Castle Road over Miners 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 September 2023.

How much traffic does Miners Castle Road over Miners River carry?

About 150 vehicles per day (2019 count), of which roughly 1% are trucks.

How long is Miners Castle Road over Miners River?

The structure is 20 ft (6.1 m) long with a longest span of 20 ft (6.1 m) and a deck 30 ft wide.

Who owns Miners Castle Road over Miners River?

It is owned by the National Park Service.