COUNTY REPORT CA

Mariposa County, California

8 ZIP codes · Home Safety Score unavailable · 0 of 8 tracked ZIP records scored

Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData

Unavailable
0 of 8 tracked ZIP records scored
8
ZIP Codes
$367K
Median Home Value
$600
Avg Remediation (0.16% of home value)

ZIP Code Risk Map

Water Quality Map: Mariposa County, California

Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.

A B C D F

Key Risk Factors

Health risk index: 14 (asthma 10.3%, diabetes 13.5%)

Modeled additional annual cost estimate per homeowner: $1,774, largest modeled factor: Wildfire

44% of homes built before 1980 (lead paint was banned for residential use in 1978)

County Health Indicators vs National Average

Asthma 10.3% (national: 8.9%)
Diabetes 13.5% (national: 10.5%)
Obesity 30.5% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1976
Median Build Year
44%
Pre-1980 Housing
51/100
Infrastructure Stress Indicator
63%
ZIPs with High Infrastructure Stress
High
Lead Pipe Risk

Modeled area-level indicator, not a failure probability. Sources: Census ACS housing age, EPA DWINSA infrastructure needs, EPA SDWIS violations, and EPA lead indicators.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $1,774

Wildfire $1,200/yr
Energy Code Gap $574/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

9,108 housing units in Mariposa County

Pre-1940 5%
1940–1959 11%
1960–1979 28%
1980–1999 40%
2000+ 16%

Source: U.S. Census Bureau ACS B25034 (Year Structure Built).

Water Safety Affordability

How much it costs to fix water issues relative to home values in Mariposa County

$367K
Median Home Value
$600
Est. Remediation Cost
0.2%
of Home Value
Remediation as % of home value low burden

Modeled remediation costs in Mariposa County can be compared with the median property value; actual costs vary by property.

Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.

Health Outcomes vs National Average

CDC PLACES data for Mariposa County residents

Asthma 10.3% (US avg: 8.9%)
Diabetes 13.5% (US avg: 11%)
Obesity 30.5% (US avg: 32.4%)

Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.

Water systems mapped to Mariposa County ZIP codes

2 community water systems mapped to Mariposa County ZIP codes; EPA may list more systems serving the county.

Systems with the most violations in Mariposa County

2 water systems with violations in EPA records.

All ZIP Codes in Mariposa County

8 ZIP codes tracked in Mariposa County.

# ZIP Code City Safety Score Grade Violations Home Value
1 93623 Fish Camp — — —
2 95306 Catheys Valley — — —
3 95311 Coulterville — — 9 (4 health) $296K
4 95318 El Portal — — $298K
5 95325 Hornitos — — —
6 95338 Mariposa — — $367K
7 95345 Midpines — — $416K
8 95389 Yosemite National Park — — $913K

Recommended Buyer Guides for Mariposa County

These buyer guides are matched by rule rather than by hand - a PFAS record adds a PFAS filter guide, a lead action-level exceedance adds lead filter guides, a high share of pre-1978 homes adds lead paint test kits, EPA Radon Zone 1 add radon kits, and a top flood or wildfire risk adds related equipment.

Overview

Mariposa County in California covers 8 tracked ZIP records. No Home Safety Score is published because the required model evidence is incomplete for every tracked record; missing evidence is not treated as zero.

1 of 1 ZIP code with a reported violation count in the available EPA record have recorded EPA violations. 4 health-based violations appear in the available health breakdown.

← Back to California Home Safety Profile

Data Sources

Reporting periods vary by source. Missing data is shown as unavailable, not as zero.

Frequently Asked Questions

How many water systems serve Mariposa County?
We map 2 public water systems to 8 ZIP codes in our data for Mariposa County. EPA may list more systems serving the county, so this is not a full count.
What is the biggest environmental risk in Mariposa County?
In ZipCheckup's cost model, the factor with the largest estimated average annual cost in Mariposa County is wildfire. Across all modeled risk factors, the estimated average additional annual cost is $1,774 per homeowner; actual costs vary by home.
How old are homes in Mariposa County?
The median home build year in Mariposa County is 1976. 44% of homes were built before 1980; homes built before 1978 may contain lead-based paint, and older homes may have older plumbing materials.

How to cite this page

APA ZipCheckup. (2026). Mariposa County, California Home Safety Profile. https://zipcheckup.com/county/california/mariposa/
BibTeX
@misc{zipcheckup-county-california-mariposa,
  author = {{ZipCheckup}},
  title  = {{Mariposa County, California Home Safety Profile}},
  year   = {2026},
  url    = {https://zipcheckup.com/county/california/mariposa/}
}

Page version: October 2026.

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