Big Four Ice Caves

At the bottom of its steep, 4,200 ft (1,300 m) high north face, debris piles form from avalanches and are able to remain there year round because of the continuous shade provided by the mountain.

[1] During the summer, snow-melt streams flow beneath the debris piles and cause caves to be formed in the ice.

Frequently exceeding several hundred hikers per day, the trailhead's two separate parking areas are often filled beyond capacity occasionally forcing hikers to park along neighboring Mountain Loop Road.

A severe autumn storm in November 2006 caused flooding of the South Fork Stillaguamish River destroying a major footbridge to the Big Four Ice Caves.

[2] While the trail is open to the public, the snowfield itself was closed temporarily[3] due to cave-ins and slides which have killed four hikers in incidents in 1998, 2010, and in 2015.