The Tsirku River is a glacially-fed stream located in Southeast Alaska near the town of Haines. The river's source is found at Tsirku Glacier, a large, sprawling ice mass at the border of Alaska and British Columbia, and ends in a massive four mile wide delta near the Tlingit village of Klukwan. While many of the feeding glaciers are primarily located in British Columbia and Canada, the river itself is completely in the United States.
After the Klehini River, the Tsirku River is the second largest tributary of the Chilkat River.