MOUNTAIN HOUSE RD
Carrying MOUNTAIN HOUSE RD over WILSON CREEK
2.8 MI S SR 101, Mendocino, California
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
MOUNTAIN HOUSE RD in Mendocino, California sits above 6% of rated California bridges on inventory load rating (17 t), while its 1912 build year is earlier than 99% of Mendocino's recorded-year cohort (357 bridges).
MOUNTAIN HOUSE RD in Mendocino, California is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 1912, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure CA:10C0144
PRE-1950 · CONCRETE · SINGLE-SPAN · TIED-CTRL · LOCAL-ADT · LIGHT-LOAD · CAT-GOOD
- PRE-1950 Pre-1950
- CONCRETE Concrete
- SINGLE-SPAN Single span
- TIED-CTRL Tied control
- LOCAL-ADT Local ADT
- LIGHT-LOAD Light load
- CAT-GOOD Good
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: MOUNTAIN HOUSE RD
The MOUNTAIN HOUSE RD bridge in Mendocino, California carries MOUNTAIN HOUSE RD over WILSON CREEK. It was built in 1912, making it 114 years old today. It was last reconstructed in 1932, extending its service life. The structure is built primarily of concrete and spans 1 section, stretching 8.1 meters (27 feet) end to end. Daily traffic averages 572 vehicles, placing it in the lower-traffic tier of California bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. None of this bridge's reported major components fall into the Poor condition range.
How MOUNTAIN HOUSE RD compares
Age against the county: built in 1912, earlier than 355 of Mendocino's 357 bridges with a recorded construction year (99%), against a county median build year of 1964. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across California bridges with a recorded inventory load rating (25,538 of 25,848 rated).
MOUNTAIN HOUSE RD vs every rated California bridge
Inventory load rating (metric tons), FHWA NBI, this state
17 Top 94% higher than 6% of 25,538 bridges
rated California bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Mendocino inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 357 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1912
- Last Reconstructed
- 1932
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 8.1 m (27 ft)
- Deck Width
- 7.9 m (26 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 572 vehicles/day
- Structure Number
- 10C0144
Condition Analysis
- • The deck (driving surface) is in good condition (7/9), showing no significant deterioration.
- • At 7/9, the superstructure (beams and supports above the deck) is in good shape and shows no significant wear.
- • The substructure (piers and abutments) is in good condition (7/9), showing no significant deterioration.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether MOUNTAIN HOUSE RD is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
- Compare MOUNTAIN HOUSE RD against other structures in Mendocino and across California. California bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for MOUNTAIN HOUSE RD?
MOUNTAIN HOUSE RD in Mendocino, California has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is MOUNTAIN HOUSE RD inspected?
MOUNTAIN HOUSE RD's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 572 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. MOUNTAIN HOUSE RD is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for MOUNTAIN HOUSE RD?
MOUNTAIN HOUSE RD has an NBI inventory load rating of 16.8 metric tons.
Who is responsible for maintaining MOUNTAIN HOUSE RD?
MOUNTAIN HOUSE RD is owned and maintained by County Highway Agency.
How old is MOUNTAIN HOUSE RD and does age affect safety?
MOUNTAIN HOUSE RD was built in 1912, making it 114 years old and last reconstructed in 1932.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.