TRUCKEE, Calif. — A major avalanche in Northern California’s Sierra Nevada has triggered a high-risk rescue operation after authorities said up to 10 backcountry skiers were missing near the Castle Peak area, west of Lake Tahoe. The slide struck Tuesday during a powerful winter storm that dumped heavy snow across the region and sharply increased avalanche danger.

Officials said a group of 16 skiers—reported to include guides and clients—was caught in or impacted by the avalanche zone. Six people were accounted for alive, while rescuers worked to locate the remaining missing skiers in extreme conditions. Search teams from multiple agencies were deployed by ski, snowcat, and specialized mountain-response units.

The Sierra Avalanche Center had rated danger as High, warning that natural avalanches were likely as new storm snow accumulated rapidly over unstable layers and was loaded by strong winds. Those conditions not only increased burial risk but also complicated rescue access, forcing crews to balance speed with responder safety amid the threat of secondary slides.

Regional infrastructure was also hit hard. Interstate 80 near Donner Summit and other mountain routes faced closures or severe travel disruptions as whiteout conditions intensified, slowing movement of emergency resources and limiting visibility in already hazardous terrain.

As night approached, families waited for updates while authorities urged the public to avoid backcountry terrain until storm conditions ease. The incident has renewed scrutiny of winter risk in one of the country’s most popular mountain recreation corridors—where beauty, speed, and unpredictability can collide in minutes.

For now, the central question remains painfully simple: whether rescuers can find survivors before weather and time erase the narrow window that defines avalanche response.