Plummer Mountain is a prominent summit of the North Cascades, in Snohomish County of Washington state. It is located west of Suiattle Pass in the heart of the Glacier Peak Wilderness on land managed by the Mount Baker-Snoqualmie National Forest. Plummer Mountain is the high point and eastern culmination of Miners Ridge. Image Lake on Miners Ridge provides a campsite from which to climb Plummer. Kennecott Copper Corporation, as of 1988, planned to dig an open-pit copper mine on the slopes of Plummer Mountain. However, protests by various advocacy groups prevented the plan from developing further.