US Bridges

Hogan Dam RD over Cosgrove Creek

Fair

Calaveras County, California · 0.2 MI E/O SR 26 · Structure no. 30C0013

Built
1941
84 years old
Condition
Fair
inspected February 2025
Type
Slab
Concrete Continuous
Length
36 ft
2 main spans
Daily traffic
1,089
2007 count
Owner
County
County Highway Agency

About this bridge

Hogan Dam RD over Cosgrove Creek is a concrete continuous slab carrying Hogan Dam RD over Cosgrove Creek in Calaveras County, California. It was built in 1941, so it is 84 years old, older than the California average of 54.8 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 1,089 vehicles a day, roughly 3% of them trucks, projected to reach 1,133 by 2047. The structure is 36 ft (11 m) long and 20 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

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CarriesHogan Dam RD
CrossesCosgrove Creek
Location0.2 MI E/O SR 26
RouteCounty Highway 0
CountyCalaveras County
StateCalifornia
Coordinates38.18523, -120.82196
Functional classRural Major 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.
Superstructure7 GoodSome minor problems.
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 inspectionFebruary 2025
Inspection intervalevery 24 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating30.8 US tons
Inventory rating18.5 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length36 ft (11 m)
Longest span20 ft (6.1 m)
Deck width20 ft (6.2 m)
Roadway width19 ft (5.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,089 (2007)
Projected traffic1,133 by 2047
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 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 Hogan Dam RD over Cosgrove Creek built?

It was built in 1941, making it 84 years old in 2025.

What condition is Hogan Dam RD over Cosgrove 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 February 2025.

How much traffic does Hogan Dam RD over Cosgrove Creek carry?

About 1,089 vehicles per day (2007 count), of which roughly 3% are trucks.

How long is Hogan Dam RD over Cosgrove Creek?

The structure is 36 ft (11 m) long with a longest span of 20 ft (6.1 m) and a deck 20 ft wide.

Who owns Hogan Dam RD over Cosgrove Creek?

It is owned by the County Highway Agency.