Redoubt Lake, or Kunaa Shak Áayi, is a long, narrow lake on Baranof Island, near Sitka, Alaska. It is located in a glacially-carved valley in Tongass National Forest. It was named Ozero Glubokoye, meaning "deep lake", in 1809 by the Russian navigator Ivan Vasilyev.Redoubt Lake is one of the largest meromictic lakes in North America. Its water is fresh to a depth of 330 ft (100 m), below which is a dense, saltwater layer.