Ishi Wilderness is a protected forty-one-thousand-acre area in the Shasta Cascade foothills of northern California, designated by Congress in 1984 to preserve a large stretch of Sierra-Cascade foothill country. Its rugged landscape of ridges, steep river canyons, basalt outcrops, caves, and pillar lava formations reflects a strongly volcanic character. Named for Ishi, identified by Alfred L. Kroeber as the last surviving Yahi, it also preserves the memory of a people who had lived here for more than three thousand years before white settlement devastated them after 1850. The wilderness also shelters important wildlife habitat, protected cultural sites, and low-impact recreation despite major burning in the Park Fire in 2024.