The mountain is composed of Shuksan greenschist, oceanic basalt that was metamorphosed when the Easton terrane collided with the west coast of North America, approximately 120 million years ago. The mountain is an eroded remnant of a thrust plate formed by the Easton collision.
Shuksan is one of the more often photographed mountains in the Cascade Range. Photographs with its reflection in Picture Lake near Mount Baker Ski Area are particularly common. The Mount Baker Highway, State Route 542, is kept open during the winter to support the ski area, and in the late summer, the road to Artist Point allows visitors to travel a few miles higher.