US Bridges

Mary Harrison Mine over Maxwell Creek

Fair

Mariposa County, California · At SH 132 · Structure no. 40C0031

Built
1926
99 years old, rebuilt 1942
Condition
Fair
inspected June 2024
Type
Girder and Floorbeam System
Steel
Length
33 ft
1 main span
Daily traffic
10
2004 count
Owner
County
County Highway Agency

About this bridge

Mary Harrison Mine over Maxwell Creek is a steel girder and floorbeam system carrying Mary Harrison Mine over Maxwell Creek in Mariposa County, California. It was built in 1926 and reconstructed in 1942, so it is 99 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 10 vehicles a day, projected to reach 12 by 2042. The structure is 33 ft (10.1 m) long and 20 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesMary Harrison Mine
CrossesMaxwell Creek
LocationAt SH 132
RouteCounty Highway 0
CountyMariposa County
StateCalifornia
Coordinates37.70781, -120.1975
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating34.3 US tons
Inventory rating20.7 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 15
Structure length33 ft (10.1 m)
Longest span31 ft (9.4 m)
Deck width20 ft (6 m)
Roadway width16 ft (5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10 (2004)
Projected traffic12 by 2042
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 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 Mary Harrison Mine over Maxwell Creek built?

It was built in 1926, making it 99 years old in 2025. It was reconstructed in 1942.

What condition is Mary Harrison Mine over Maxwell 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 June 2024.

How much traffic does Mary Harrison Mine over Maxwell Creek carry?

About 10 vehicles per day (2004 count).

How long is Mary Harrison Mine over Maxwell Creek?

The structure is 33 ft (10.1 m) long with a longest span of 31 ft (9.4 m) and a deck 20 ft wide.

Who owns Mary Harrison Mine over Maxwell Creek?

It is owned by the County Highway Agency.