Each fall, the Chilkat River north of Haines  becomes home to the largest eagle gathering on earth. Throughout the summer, water flows into a massive underground reservoir created by gravel deposits at the confluence of the Tsirku, Klehini, and Chilkat Rivers north of Haines. When fall arrives this water percolates upward, keeping river temperatures above freezing.
These warm waters attract an unusual late run of spawning chum and silver salmon. The dying salmon attract bears, wolves, gulls, magpies, ravens, and up to 3,500 bald eagles along a four-mile stretch of river just below the Tlingit village of Klukwan (pop. 140). Covering 48,000 acres, the Chilkat Bald Eagle Preserve (907/766-2292, www.dnr.state.ak.us ) protects this unique gathering of eagles.
During the peak of the salmon run (Nov.–Jan.), black cottonwoods along the river are filled with hundreds of birds, and many more line the braided riverbanks. The area is very popular with photographers, but be sure to stay off the flats to avoid disturbing these majestic birds. During the summer, local eagle populations are much lower, but with 80 active nests and up to 400 resident eagles on the river, you’re guaranteed to see some eagles.
A state campground ($10) is at Mosquito Lake, five miles north of Klukwan and three miles off the highway. Tours by van or boat go through the bald eagle preserve, and the Alaska Bald Eagle Festival  in mid-November brings more tours and educational workshops.