US Bridges

Mountain House RD over Cummiskey Creek

Fair

Mendocino County, California · 2.2 MI N SR 128 · Structure no. 10C0143

Built
1913
112 years old
Condition
Fair
inspected February 2024
Type
Tee Beam
Concrete
Length
64 ft
2 main spans
Daily traffic
1,252
2011 count
Owner
County
County Highway Agency

About this bridge

Mountain House RD over Cummiskey Creek is a concrete tee beam carrying Mountain House RD over Cummiskey Creek in Mendocino County, California. It was built in 1913, so it is 112 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 1,252 vehicles a day, roughly 5% of them trucks, projected to reach 1,203 by 2042. The structure is 64 ft (19.6 m) long and 23 ft wide. If it were closed, the detour would be 21.7 mi (35 km).

Location

Open in Google Maps
CarriesMountain House RD
CrossesCummiskey Creek
Location2.2 MI N SR 128
RouteCounty Highway 0
CountyMendocino County
StateCalifornia
Coordinates38.90087, -123.08935
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
Deck7 GoodSome minor problems.
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 protection7 GoodSome minor problems.
Last inspectionFebruary 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 geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating26.8 US tons
Inventory rating20.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length64 ft (19.6 m)
Longest span31 ft (9.6 m)
Deck width23 ft (7.1 m)
Roadway width21 ft (6.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,252 (2011)
Projected traffic1,203 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed21.7 mi (35 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Mountain House RD over Cummiskey Creek built?

It was built in 1913, making it 112 years old in 2025.

What condition is Mountain House RD over Cummiskey 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 2024.

How much traffic does Mountain House RD over Cummiskey Creek carry?

About 1,252 vehicles per day (2011 count), of which roughly 5% are trucks.

How long is Mountain House RD over Cummiskey Creek?

The structure is 64 ft (19.6 m) long with a longest span of 31 ft (9.6 m) and a deck 23 ft wide.

Who owns Mountain House RD over Cummiskey Creek?

It is owned by the County Highway Agency.