Tuolumne County, CA Fire Regulations: Wildfire Zones (2026)

Tuolumne County faces extreme wildfire risk - the 2013 Rim Fire burned roughly 257,000 acres, one of California's largest. The state classifies wildfire risk through Fire Hazard Severity Zones (FHSZ). CAL FIRE / the Office of the State Fire Marshal released updated State Responsibility Area FHSZ maps (effective 2022-2024) for the first time in about 15 years; reporting on the Tuolumne County maps shows more than 358,000 acres in zones graded moderate, high, and very high. Compared to the prior 2007 maps, about 12.8% of county SRA acreage that used to be moderate is now high or very high - roughly 10.6% more in high and 2.2% more in very high zones. The SRA maps cover state-responsibility lands and do not include the incorporated City of Sonora, a Local Responsibility Area addressed separately. Being mapped in an FHSZ carries legal consequences: it triggers California Public Resources Code 4291's 100-foot defensible space requirement around structures and the new building/wildfire material standards in higher-risk zones, and it overlaps with Tuolumne County's Hazardous Vegetation Management Ordinance (Chapter 8.14) requiring vegetation clearance on private parcels in the unincorporated county. Property owners should look up their parcel on CAL FIRE's FHSZ viewer to confirm their zone and the obligations that follow. Verify current map status and any local building requirements with Tuolumne County Fire Prevention (209-533-5502) and CAL FIRE Tuolumne-Calaveras Unit.