Challis Arc

The Challis Arc was an Eocene volcanic field that stretched from southwestern British Columbia through Washington to Idaho, United States. The volcanic field extended between 42 and 49 degrees north latitude and was about 1500 kilometers in length. It exhibited volcanic activity for about 10 million years. Remnants of the Challis Arc are found as granitic plutons in the North Cascades, the Okanagan Highlands and in southcentral Idaho.

Challis Arc

The Challis Arc was an Eocene volcanic field that stretched from southwestern British Columbia through Washington to Idaho, United States. The volcanic field extended between 42 and 49 degrees north latitude and was about 1500 kilometers in length. It exhibited volcanic activity for about 10 million years. Remnants of the Challis Arc are found as granitic plutons in the North Cascades, the Okanagan Highlands and in southcentral Idaho.