KLAMATH RIVER ROAD
Carrying KLAMATH RIVER ROAD over HUMBUG CREEK
AT HUMBUG CREEK RD, Siskiyou, California
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
KLAMATH RIVER ROAD in Siskiyou, California sits above 99% of rated California bridges on inventory load rating (66 t), while its 1975 build year is earlier than 28% of Siskiyou's recorded-year cohort (421 bridges).
KLAMATH RIVER ROAD in Siskiyou, California is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 1975, 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:02C0118
INTERSTATE-ERA · STEEL · SINGLE-SPAN · TIED-CTRL · TRACE-ADT · HEAVY-LOAD · CAT-GOOD
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- SINGLE-SPAN Single span
- TIED-CTRL Tied control
- TRACE-ADT Trace ADT
- HEAVY-LOAD Heavy 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: KLAMATH RIVER ROAD
The KLAMATH RIVER ROAD bridge in Siskiyou, California carries KLAMATH RIVER ROAD over HUMBUG CREEK. It was built in 1975, making it 51 years old today. The structure is built primarily of steel and spans 1 section, stretching 18.4 meters (60 feet) end to end. Daily traffic averages 20 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. No reported major component scores in the Poor range under the current federal condition thresholds.
How KLAMATH RIVER ROAD compares
Age against the county: built in 1975, earlier than 119 of Siskiyou's 421 bridges with a recorded construction year (28%), against a county median build year of 1969. This is one of the newer structures in its county.
Live comparison across California bridges with a recorded inventory load rating (25,538 of 25,848 rated).
KLAMATH RIVER ROAD vs every rated California bridge
Inventory load rating (metric tons), FHWA NBI, this state
66 Top 1% higher than 99% 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.
Siskiyou inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 421 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
- 1975
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 18.4 m (60 ft)
- Deck Width
- 6.3 m (21 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 20 vehicles/day
- Structure Number
- 02C0118
Condition Analysis
- • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
- • The superstructure (beams and supports above the deck) rates good at 7/9, with no significant deterioration on file.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
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 KLAMATH RIVER ROAD 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 KLAMATH RIVER ROAD against other structures in Siskiyou 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 KLAMATH RIVER ROAD?
KLAMATH RIVER ROAD in Siskiyou, 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 KLAMATH RIVER ROAD inspected?
KLAMATH RIVER ROAD'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 20 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. KLAMATH RIVER ROAD 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 KLAMATH RIVER ROAD?
KLAMATH RIVER ROAD has an NBI inventory load rating of 66.4 metric tons.
Who is responsible for maintaining KLAMATH RIVER ROAD?
KLAMATH RIVER ROAD is owned and maintained by County Highway Agency.
How old is KLAMATH RIVER ROAD and does age affect safety?
KLAMATH RIVER ROAD was built in 1975, making it 51 years old.
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.