Sitka National Historical Park is located at the mouth of Indian River on Baranof Island. Indian River drains the post-glaciated valley encompassing approximately 7,800 acres, outlined by Mount Verstovia, Arrowhead Peak, the Sisters, and Gavan Hill. The park coastline is adjacent to Crescent and Jamestown Bays.

Baranof Island is one of the most rugged of all the islands in southeast Alaska, with many high peaks and slopes. The outer coast is dotted with numerous small islands. The northern part of the island exhibits soil layers of volcanic ash from past eruptions of Mt. Edgecumbe.