Mount Edgecumbe (3,202 ft or 976 m) is located on southern Kruzof Island, which bounds Sitka Sound to the west, is the highest peak in a range of dormant volcanoes. The volcanic field became active about 611,000 years ago and peaked in activity in the Pleistocene, about 11,250 years ago. Ash from this period blanketed all of Sitka and reached to Juneau. The most recent eruptions were about 4,000 years ago and were more limited in impact.