Title 24 Reports in Mariposa County

Zone 16 is the park side

Three of the county's eight ZIP codes are zone 16, and each is a Yosemite address or a gateway to one. 95318 is El Portal, at the park's western entrance on Highway 140. 93623 is Fish Camp, on Highway 41 south of the park. 95389 covers Wawona, Yosemite West and Yosemite Valley itself.

The other five are zone 12: Mariposa, Midpines and Catheys Valley along Highway 140, Hornitos to the west, Coulterville and Greeley Hill to the north-west.

Lower than the town, colder on paper

El Portal is the instructive one. At the Census Bureau's reference point for each community, USGS elevation data puts El Portal at about 1,900 feet and the town of Mariposa at about 2,000 feet — so El Portal, if anything, is the lower of the two. Yet 95318 is zone 16 and 95338 is zone 12.

The Energy Commission assigns one zone to each ZIP code, so the zone describes the ZIP as a whole rather than any single lot inside it. Which is why the check is made against the published table, not estimated from a map or a contour line.

One highway, both zones

Highway 140 shows the split in a single drive. Catheys Valley, Mariposa and Midpines are zone 12; El Portal, next along the road, is zone 16. Two jobs a short drive apart can need reports written to different targets — zone 12's hot summers on one, zone 16's heating-led requirements on the other.

No incorporated city

Mariposa County has no incorporated city on the California Department of Finance's 2026 estimates; the town of Mariposa is an unincorporated community. Where a county has cities, a project inside one is permitted by the city and the rest by the county. Here, federal land in the park aside, the county is the permitting authority everywhere.

Every ZIP code by zone

Zones per the Energy Commission; county membership and community names per the 2020 Census.

• Climate zone 12 — 95306 (Catheys Valley); 95311 (Greeley Hill, Lake Don Pedro, Coulterville); 95325 (Hornitos); 95338 (Mariposa, Bootjack, Bear Valley, Mt. Bullion, Hornitos); 95345 (Midpines)
• Climate zone 16 — 93623 (Fish Camp); 95318 (El Portal); also 95389, split with a neighbouring county (below)

A ZIP code that crosses the county line

• 95389 (Wawona, Crane Creek, Yosemite West) — about 82% within Mariposa County, the remainder in Tuolumne 18%

The park runs over the county line, and so does its ZIP code: Tuolumne County holds part of 95389. The zone is 16 on both sides; the line decides only whether Mariposa or Tuolumne County is the permitting authority for private land.

Finding the zone for your own project

The zone is set by the project's location and confirmed from the ZIP code against the Energy Commission's published table — not from the county name and not from the nearest large town. Because Mariposa County contains more than one zone, that check decides which set of numbers a report is written against.

Give us the project address and we determine the zone as part of preparing the report. It is the first thing established, because every insulation, glazing and equipment figure downstream depends on it.

Climate zones in Mariposa County

Mariposa County contains California climate zones 12 and 16. The zone drives the insulation, glazing and equipment performance a report has to demonstrate, and it is confirmed from the project ZIP code against the Energy Commission's published table.