Property Tax Appeals in Mariposa County, California
Mariposa County's Board of Equalization page states that, effective January 18, 2022, Ordinance 1170 dissolved the former Assessment Appeals Board, and the Board of Supervisors now sits as the Board of Equalization. As of 2024, per Resolution 2024-237, all applications require a non-refundable $30 filing fee, payable by cash or check made payable to Mariposa County; applications submitted without payment are rendered invalid. The page states Regular Assessments must be filed July 2nd to December 1st of each year, while the state's certified 2026 table lists Mariposa's regular period as ending November 30, 2026. Applications are mailed to the Clerk of the Board of Supervisors, P.O. Box 784, Mariposa, CA 95338, phone 209-966-3222. FairPath can help an owner organize a comparison table, condition photos, official links, and a filing checklist. It does not file the application, choose the owner's opinion of value, pay the fee, or communicate with the Assessor's Office or the Board on the owner's behalf.
Assessment context: Begin with the Assessor's parcel record and confirm whether the dispute concerns the January 1, 2026 lien-date value on the regular roll, a supplemental assessment tied to a change of ownership or new construction, or an escape assessment, since the Board of Equalization page states each carries its own filing clock. Mariposa County serves as the historic gateway to Yosemite National Park, anchored by the Gold Rush-era county seat of Mariposa, with Sierra Nevada foothill ranchland, oak woodland, and the Lake McClure and Lake McSwain reservoir communities spreading toward the park's granite high country. A property a few miles away can sit in a very different foothill, forested, or reservoir-adjacent setting, so land use and wildfire exposure should be confirmed against the Assessor's record rather than assumed from a map.
Filing process: Mariposa County's Board of Equalization page states an owner is urged to discuss the assessment with the Assessor's Office first, since contact does not itself protect the right to appeal; the owner must still file an Assessment Appeal Application by the filing deadline to preserve that right. The completed application, with the non-refundable $30 filing fee paid by cash or check payable to Mariposa County, is mailed to the Clerk of the Board of Supervisors, P.O. Box 784, Mariposa, CA 95338, phone 209-966-3222; applications submitted without payment are rendered invalid. Applications postmarked by the last day of the filing period are considered timely filed, and the Board has no jurisdiction to hear an application filed outside the specified time. After filing, the Clerk of the Board schedules a hearing and generally sends written notice 45 days before the hearing date, and the county has up to two years to schedule it.
Evidence to review: Mariposa County's Board of Equalization page states the law presumes the Assessor has properly valued the property, so the applicant must present evidence to support a different value or the application must be denied, except for an owner-occupied single-family dwelling, where the Assessor must present evidence supporting its valuation. The page describes comparable sales as the preferred method when reliable market data is available, noting that sales data may be from any time prior to the required appraisal date but not more than 90 days after, with adjustments for differences such as size, age, condition, quality, and location; a single sale price, even of the subject property, does not by itself establish market value. For foothill, reservoir-adjacent, or Yosemite-gateway parcels, document acreage, water access, and any wildfire-related site conditions with dated photographs, since terrain and hazard exposure vary widely across Mariposa County's geography.
Current deadline guidance: 2026 regular assessment appeals: the State Board of Equalization lists November 30, 2026; Mariposa County's page says July 2 to December 1. Confirm the date with the Clerk of the Board. Mariposa County's Board of Equalization page states that Regular Assessments must be filed 'July 2nd to December 1st of each year for all real and personal property assessments,' and the California State Board of Equalization's certified 2026 filing-period table lists Mariposa County's 2026 regular period as ending November 30, 2026. Supplemental and escape assessments instead run no later than 60 days of the mailing date printed on the notice or tax bill, or the postmark date, whichever is later.
Mariposa County's Board of Equalization page states the Regular Assessment filing period as July 2nd to December 1st each year; the state's certified 2026 table lists Mariposa's 2026 period as ending November 30, 2026.
Effective 2024, per Resolution 2024-237, Mariposa County charges a non-refundable $30 filing fee per application, payable by cash or check to Mariposa County, or the application is invalid.
Ordinance 1170 dissolved Mariposa's former Assessment Appeals Board in 2022; the Board of Supervisors now sits directly as the Board of Equalization.
Mariposa County serves as the historic gateway to Yosemite National Park, spanning Gold Rush foothill towns and the Lake McClure and Lake McSwain reservoir communities.
Official filing authority: Mariposa County Clerk of the Board of Supervisors, Board of Equalization. https://www.mariposacounty.gov/120/Assessment-Appeals
Source: Mariposa County, Board of Equalization (Assessment Appeals), https://www.mariposacounty.gov/120/Assessment-Appeals. Reviewed 2026-09-22.
Source: Mariposa County, Assessor, https://www.mariposacounty.gov/109/Assessor. Reviewed 2026-09-22.
Source: California State Board of Equalization, Letter to Assessors 2026/023: 2026 Assessment Appeal Filing Periods, https://boe.ca.gov/proptaxes/pdf/lta26023.pdf. Reviewed 2026-09-22.
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