County guide

Zone 0 in Mariposa County: a 1980 clearing duty at the Yosemite gate, read through a door the publisher left open

Fact-checked August 23, 2026·Sources at the end of this article

Two sets of rules, and neither one binds your fence today

As of August 23, 2026 we could find no Zone 0 or ember-resistant-zone requirement in force in Mariposa County. We read the operative texts from the county publisher's own live pages, through a print endpoint it leaves open beside its login-gated reader, so this is a current read, not an archive. The county's homeowner-facing instrument is Ordinance 550 of July 1980: anyone who owns, leases, controls, operates or maintains any building or structure in the county must keep a thirty-foot firebreak of cleared flammable vegetation around it, extendable to one hundred feet where the county fire warden finds extra-hazardous conditions, with ten feet of chimney clearance and tree maintenance on top. It is the state's defensible-space framework restated as county law, four decades ago, and it applies countywide to every structure, not just new ones.

The 1980 chapter has one provision we have seen nowhere else: the fire warden may exempt structures "constructed entirely of nonflammable materials" from the clearing requirements. Noncombustible construction as a way out of vegetation work is the survey's neatest inversion of the Zone 0 idea, which asks for noncombustible material precisely in addition to clearing. The county's newest fire enactment, from September 30, 2025, adopts the state's 2025 Wildland-Urban Interface Code with its appendices, unamended: construction standards for new building in the interface, exactly as the state wrote them, with no local additions. Nothing in either instrument, or anywhere else in the code, regulates the first five feet or what a fence is made of, and "defensible" returns zero results in the county code's own search index.

Adopted, not yet in effect: the statewide Zone 0 regulation. It cleared the Board of Forestry on August 19, 2026 and still needs Office of Administrative Law review and publication by the Secretary of State, so no compliance clock is running. Our timeline and enforcement guide covers the phase-in, and the register lists the eighteen jurisdictions we can prove have Zone 0 rules in force. None is in Mariposa County.

Where the statewide rule will reach in this county

Everywhere that is private land, effectively. Mariposa has no incorporated cities, so Mariposa town, Coulterville, Hornitos, Catheys Valley, Ponderosa Basin, Lushmeadows, Midpines and El Portal along the 140 corridor into Yosemite all answer to the county code and state law with no municipal layer anywhere. Nearly all of it is State Responsibility Area, where the rule covers every hazard class under Public Resources Code section 4291 on the five-year existing-home clock once effective, including the neighborhoods the 2022 Oak Fire burned through near Midpines and Jerseydale. Start with our address lookup walkthrough.

Claims we could not verify

• The fire districts' rules. Mariposa County Fire and any district-level instruments were not read.
• How often the warden's hundred-foot extension is invoked. The code grants the power; practice is a records question.

What this means for you

• Do not buy a fence because you think Mariposa County requires one. The 1980 duty is about cleared vegetation, not materials. The statewide rule, once effective, asks for a five-foot noncombustible span where a fence attaches to the house; our fence requirements guide quotes the adopted text.
• The thirty-foot duty is county law today, on every structure. It has been since 1980, the warden can require more, and peace officers can enforce it. The free first-five-feet work is where an inspection is won or lost.
• Check your track while nothing is due. Check your address against CAL FIRE's own layers, then walk the first five feet with our self-assessment, which also flags what you do not need to buy.

How often CAL FIRE inspects here

CAL FIRE has 732 parcels in Mariposa County in its defensible space inspection program in July 2026, the month the dashboard is currently reporting. Of the 701 inspected, 632 were compliant, which is 90 percent. 3 properties have already been found non-compliant more than once.

Two things this does not tell you. These counts cover inspections by CAL FIRE and Contract Counties inside the State Responsibility Area only, so work done by local fire agencies in the Local Responsibility Area is absent entirely. And none of these inspections is checking Zone 0: they are inspections against the defensible space rules in force today, which reach from the structure out to one hundred feet and contain no ember-resistant zone requirement. See the full inspection figures and what they mean, read from CAL FIRE's public dashboard on August 23, 2026.

Not the county you were looking for? See every jurisdiction we can prove has a rule in force, and ask us to add yours.