To Zapata Falls trailhead, take 150 about 10 miles north from its connection with 160. Turn right at the signed dirt road to Zapata Falls. Follow this improved dirt road to its end at the well-developed trailhead. It's not far, and even my lowered Miata made it without scraping.
Take the wide trail to Zapata Falls, where a sign indicates the continuation trail to Zapata Lake. Follow it toward Zapata Lake and past the second stream crossing (California Gulch drainage), at which point the trail climbs onto the ridge south of California Gulch (this is California Peak's west ridge). At the top of the ridge, a less traveled trail breaks to the left (east). It is marked by aspen logs on either side of the trail as well as a living aspen into which some jerk carved, "north fork trail". This trail is faint at times. The Roachs' 13ers guidebook indicates the route following the ridge all the way to the peak, but after a little while the trail decends down the south side of the ridge into the north fork drainage. After passing under a large talus slope, my party left the trail and ascended the ridge directly via talus and loose dirt slopes, gaining the ridge at treeline (12000ft/3660m). This route would be better as a snowclimb in spring or early summer to prevent erosion of the slope.
From the treeline, simply follow the class 2 ridge up to the peak.
The 10 essentials should be fine later in the season. Crampons and axe would be nice for ascending the ridge from the North Fork Drainage earlier in the season.
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