Mariposa County, CA Fire Regulations: Brush Clearance (2026)

Mariposa County is entirely unincorporated and falls within a CAL FIRE State Responsibility Area, so the controlling brush-clearance law is California Public Resources Code (PRC) section 4291. PRC 4291 requires owners of structures in or adjoining mountainous, forest-covered, brush-covered, or grass-covered land to 'maintain defensible space of 100 feet from each side and from the front and rear of the structure, but not beyond the property line.' The statute and CAL FIRE guidance divide that 100 feet into zones: an ember-resistant 'Zone 0' within 5 feet of the structure (no combustible mulch, vegetation, or stored fuels), with more intense fuel reduction between 5 and 30 feet (Zone 1 - remove dead and dying plants, keep grass low, clear leaves from roofs and gutters, and space out shrubs), and a 'reduced fuel' Zone 2 from 30 to 100 feet (thin vegetation, prune lower tree branches, and break up continuous fuels). A greater distance can be required by other state law or local ordinance. CAL FIRE conducts defensible-space inspections in the SRA, and locally the Mariposa Fire Safe Council offers free residential chipping and brush-clearing programs and home-hardening assessments to help owners comply; chipping piles must be placed within 10 feet of a roadway. Given the county's severe wildfire history (Oak, Ferguson, and Detwiler fires), defensible space is treated as a critical, enforceable requirement rather than a suggestion.