HAPPY ISLES LOOP
Carrying HAPPY ISLES LOOP over MERCED RIVER
Approximately 500' downst, Mariposa, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: HAPPY ISLES LOOP
The HAPPY ISLES LOOP bridge in Mariposa, California carries HAPPY ISLES LOOP over MERCED RIVER. It was built in 1929, making it 97 years old today. The structure is built primarily of concrete and spans 3 sections, stretching 37.8 meters (124 feet) end to end. Daily traffic averages 50 vehicles, placing it in the lower-traffic tier of California 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. All reported major components score above the Poor range. Its NBI inventory load rating is 19.0 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How HAPPY ISLES LOOP compares
Live comparison across California.
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 How the historical reference is calculated.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
- 1929
- Material
- Concrete
- Number of Spans
- 3
- Structure Length
- 37.8 m (124 ft)
- Deck Width
- 12.2 m (40 ft)
- Owner
- National Park Service
- Avg Daily Traffic
- 50 vehicles/day
- Structure Number
- 8800009S0000000
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.
- • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
How to read this record
This page shows what the last federal inspection recorded, not whether HAPPY ISLES LOOP 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 HAPPY ISLES LOOP against other structures in Mariposa 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 HAPPY ISLES LOOP?
HAPPY ISLES LOOP in Mariposa, California 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 HAPPY ISLES LOOP inspected?
HAPPY ISLES LOOP'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. HAPPY ISLES LOOP 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 HAPPY ISLES LOOP?
HAPPY ISLES LOOP has an NBI inventory load rating of 19.0 metric tons.
Who is responsible for maintaining HAPPY ISLES LOOP?
HAPPY ISLES LOOP is owned and maintained by National Park Service.
How old is HAPPY ISLES LOOP and does age affect safety?
HAPPY ISLES LOOP was built in 1929, making it 97 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.
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.