US Bridges

Cliff Drive over Gratiot River

Poor

Keweenaw County, Michigan · 4.0 MI N of Ahmeek Villag · Structure no. 000000000005265

Built
1935
90 years old
Condition
Poor
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
24 ft
1 main span
Daily traffic
128
2023 count
Owner
County
County Highway Agency

About this bridge

Cliff Drive over Gratiot River is a steel stringer/multi-beam or girder carrying Cliff Drive over Gratiot River in Keweenaw County, Michigan. It was built in 1935, so it is 90 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 128 vehicles a day, projected to reach 156 by 2043. The structure is 24 ft (7.3 m) long and 31 ft wide. If it were closed, the detour would be 11.8 mi (19 km).

Location

Open in Google Maps
CarriesCliff Drive
CrossesGratiot River
Location4.0 MI N of Ahmeek Villag
RouteCounty Highway 0
CountyKeweenaw County
StateMichigan
Coordinates47.34236, -88.34308
Functional classRural Minor Collector

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2024
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 adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating92.2 US tons
Inventory rating55.3 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length24 ft (7.3 m)
Longest span20 ft (6.2 m)
Deck width31 ft (9.3 m)
Roadway width29 ft (8.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic128 (2023)
Projected traffic156 by 2043
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed11.8 mi (19 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was Cliff Drive over Gratiot River built?

It was built in 1935, making it 90 years old in 2025.

What condition is Cliff Drive over Gratiot 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 October 2024.

How much traffic does Cliff Drive over Gratiot River carry?

About 128 vehicles per day (2023 count).

How long is Cliff Drive over Gratiot River?

The structure is 24 ft (7.3 m) long with a longest span of 20 ft (6.2 m) and a deck 31 ft wide.

Who owns Cliff Drive over Gratiot River?

It is owned by the County Highway Agency.