In June 2020, the Bighorn Fire ignited on the south face of the Santa Catalina Mountains directly above the Catalina Foothills. Over the following weeks, the fire burned more than 119,000 acres and came within a mile of residential neighborhoods in the Foothills. Thousands of residents were placed under evacuation orders. Homes throughout the Foothills sustained significant smoke and soot damage even while the fire never crossed into the residential areas. The Bighorn Fire was a defining event for Catalina Foothills homeowners — and it left important lessons that remain relevant every fire season.
What Foothills Homes Experienced During the Bighorn Fire
The Bighorn Fire burned for weeks during exceptionally dry, windy conditions. Foothills residents who remained in or near evacuation zones experienced:
- Pervasive smoke infiltration: With a fire burning directly above the community for weeks, smoke concentrations reached levels that infiltrated even well-sealed homes. HVAC systems, attic vents, and normal building gaps allowed continuous particle deposition throughout interiors.
- Soot fallout: Ash and soot particles fell across Foothills properties throughout the fire, settling on pools, landscaping, exterior surfaces, and any interior areas that were accessed during the fire period.
- HVAC contamination: Homeowners who failed to switch HVAC systems to recirculation mode during the fire ended up with smoke particles throughout their ductwork and air handler components, requiring complete duct cleaning before safe occupancy.
- Post-fire flooding risk: The subsequent 2020 monsoon season brought debris flows and increased runoff from the burned mountain slopes directly above the Foothills — a post-fire flood risk that persisted for several years after the fire.
Post-Wildfire Flooding: The Hidden Secondary Risk
One lesson the Bighorn Fire underscored for Foothills homeowners: wildfires create a significant secondary water damage risk that lasts years after the fire itself is extinguished. Burned mountain slopes lose the vegetation that slows water movement and anchors soil. The result is faster, more voluminous runoff and debris-laden water flows during subsequent monsoon seasons. Homes below burn scars face elevated flooding risk for 3–5 years after a major fire event.
If the Santa Catalinas experience another significant fire, Foothills homeowners should:
- Consult with a drainage engineer about post-fire runoff changes on slopes above their property.
- Install or upgrade drainage swales and debris screens on any channels approaching the home.
- Ensure homeowners and flood insurance is current and adequate for the elevated post-fire risk period.
Preparing Your Foothills Home for the Next Fire Season
- Install ember-resistant attic vent covers — standard soffit and gable vents are primary ember intrusion points.
- Create a 5-foot non-combustible zone immediately around the home's foundation — no wood mulch, combustible plants, or stored materials.
- Replace any wood decks, fences, or trellises adjacent to the home with composite or non-combustible alternatives.
- Have HVAC filters upgraded to MERV-13 and ensure the system can recirculate without drawing outside air.
- Know your evacuation zone designation and have a go-bag prepared for rapid departure.