Boston Glacier

Boston Glacier is the largest ice mass in North Cascades National Park, situated in a deep valley beneath Forbidden Peak and Boston Peak. The frozen surface spreads across a wide basin surrounded by steep rock walls and ridge lines that frame its expanse.

The glacier formed during ancient ice ages and has retreated significantly since the mid-1800s. A temporary pause in this melting occurred for several decades in the mid-1900s before further decline resumed.

Scientists regularly monitor Boston Glacier as part of research programs focusing on climate patterns and glacier behavior in the North Cascades region.

Reaching this location demands preparation for high altitude conditions in a remote mountain environment with no facilities or services. Visitors should expect uneven terrain, changing weather, and challenging trail sections that require experience.

A dramatic icefall cascades at the glacier's lower end, resembling a frozen waterfall where ice tumbles over steep rock ledges. This striking feature forms as the frozen mass moves downward under its own weight.

Location: Washington

GPS coordinates: 48.50610,-121.03400

Latest update: December 14, 2025 13:00