THORNTON LAKES ROA
Carrying THORNTON LAKES ROA over THORNTON CREEK
Turn left from Route 20 a, Skagit, Washington
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: THORNTON LAKES ROA
The THORNTON LAKES ROA bridge in Skagit, Washington carries THORNTON LAKES ROA over THORNTON CREEK. It was built in 1952, making it 74 years old today. It was last reconstructed in 1979, extending its service life. The structure is built primarily of wood or timber and spans 1 section, stretching 15.5 meters (51 feet) end to end. Daily traffic averages 50 vehicles, placing it in the lower-traffic tier of Washington bridges. It is owned and maintained by National Park Service.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 6/9, substructure at 6/9. The weakest component sits in fair condition. None of this bridge's reported major components fall into the Poor condition range. Its NBI inventory load rating is 20.0 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How THORNTON LAKES ROA compares
Live comparison across Washington.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1952
- Last Reconstructed
- 1979
- Material
- Wood or Timber
- Number of Spans
- 1
- Structure Length
- 15.5 m (51 ft)
- Deck Width
- 4.1 m (13 ft)
- Owner
- National Park Service
- Avg Daily Traffic
- 50 vehicles/day
- Structure Number
- 9470003P0000000
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • The superstructure (beams and supports above the deck) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • At 6/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
How to read this record
This page shows what the last federal inspection recorded, not whether THORNTON LAKES ROA 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 THORNTON LAKES ROA against other structures in Skagit and across Washington. Washington 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 THORNTON LAKES ROA?
THORNTON LAKES ROA in Skagit, Washington has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is THORNTON LAKES ROA inspected?
THORNTON LAKES ROA'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 50 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. THORNTON LAKES ROA is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for THORNTON LAKES ROA?
THORNTON LAKES ROA has an NBI inventory load rating of 20.0 metric tons.
Who is responsible for maintaining THORNTON LAKES ROA?
THORNTON LAKES ROA is owned and maintained by National Park Service.
How old is THORNTON LAKES ROA and does age affect safety?
THORNTON LAKES ROA was built in 1952, making it 74 years old and last reconstructed in 1979.
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.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.