Yosemite National Park, CA Radon Mitigation and Testing

Q: What EPA Radon Zone is Yosemite National Park in?

Yosemite National Park is in Mariposa County, EPA Zone 2.

Q: How much does radon mitigation cost in Yosemite National Park?

Radon mitigation typically costs between $800 and $2,000. Most standard systems fall in the $1,000-$1,500 range.

Mariposa County

EPA Zone 2

Within Mariposa County's Sierra Nevada foothills, Yosemite National Park encompasses granite formations and metamorphic rocks that typically produce lower radon levels than sedimentary regions. The limited residential structures in zip code 95389 consist primarily of park service housing and visitor facilities built to modern construction standards. Given the area's geological composition and limited testing data, radon levels are generally expected to be moderate, though testing remains advisable for residential structures.

Yosemite National Park, CA Radon Mitigation

Professional radon mitigation is the most effective way to permanently lower radon levels and protect your household.

Yosemite National Park, CA Radon Testing

Finding qualified radon testing professionals is the first step toward protecting your home.

Yosemite National Park Radon Facts

Key details about the radon risk profile for Yosemite National Park and the 95389 zip code area.

EPA Radon Zone

Zone 2 — Moderate Risk

County

Mariposa County, CA

Zip Code

95389

Predicted Screening Level

2–4 pCi/L (Zone 2)

Yosemite National Park and the 95389 zip code are located in Mariposa County, which has an EPA assigned Radon Zone of 2. A radon zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L. The EPA recommends testing every home regardless of zone classification.

Radon FAQ for Yosemite National Park, CA

What EPA Radon Zone is Yosemite National Park in?

Yosemite National Park and the 95389 zip code are in Mariposa County, which has an EPA assigned Radon Zone of 2. A zone of 2 predicts an average indoor radon screening level between 2 and 4 pCi/L.

How much does radon mitigation cost in Yosemite National Park?

Radon mitigation in Yosemite National Park typically costs between $800 and $2,000. Most homes with standard basements can be mitigated with a sub-slab depressurization system in the $1,000–$1,500 range. Factors that can increase cost include complex foundations, crawl spaces, or very high radon levels.

Should I test for radon if I'm buying a home in Yosemite National Park?

Yes. Radon testing should be part of every home purchase. A short-term radon test is typically included as part of the home inspection process and costs $150–$250. If elevated levels are found, you can negotiate mitigation as part of the sale.

Most Active Radon Markets in California

Cities with the most user-submitted radon test data in the state.

City	Avg User Radon Level	Submissions
Los Angeles	7.83 pCi/L	6
Mammoth Lakes	10.80 pCi/L	5
San Jose	4.20 pCi/L	5
Rancho Palos Verdes	8.00 pCi/L	4
Woodland Hills	7.67 pCi/L	3
South Lake Tahoe	6.33 pCi/L	3
Palos Verdes Peninsula	6.00 pCi/L	3
Bishop	5.67 pCi/L	3
Sacramento	4.33 pCi/L	3
Oakland	3.33 pCi/L	3
Fresno	10.00 pCi/L	2
Davis	8.00 pCi/L	2
Palo Alto	6.50 pCi/L	2
Studio City	6.50 pCi/L	2
Menlo Park	5.00 pCi/L	2
Truckee	5.00 pCi/L	2
Walnut Creek	4.00 pCi/L	2
San Diego	3.50 pCi/L	2
San Francisco	3.50 pCi/L	2
Belmont	20.00 pCi/L	1