The Harrison River in southern British Columbia hosts North America's largest annual congregation of bald eagles. Thousands of bald eagles migrate to this area, particularly the confluence of the Chehalis River and the Harrison, from October through February to feed on spawning salmon. This region, known as Bald Eagle Flats, provides gravel bars and channels essential for salmon egg deposition.
Approximately 35,000 to 50,000 bald eagles travel to the Harrison River from various locations, including Alaska. This migration is influenced by the freezing of northern lakes and rivers, which restricts the eagles' ability to fish. The Harrison River, an 18km tributary of the Fraser River, remains unfrozen year-round and supports all five species of Pacific salmon during their spawning cycles. This consistent food source attracts a significant number of eagles.
The abundance of dead salmon benefits the wider ecosystem, providing sustenance for insects, waterfowl such as ducks, geese, and swans, and other aquatic life. White sturgeon, recognized as the largest freshwater fish in North America, are also drawn to the river by the scent of decaying salmon. These sturgeon utilize the spawning channels to access salmon eggs.
Historically, bald eagles in the region faced persecution. In the 1950s, a bounty system in areas like Blaine, Washington, led to eagles being hunted due to perceived threats to commercial fishing. Conservation efforts initiated since then have contributed to a population recovery. The Fraser Valley, which encompasses the Harrison River, now supports approximately 700 breeding pairs of bald eagles.
The annual eagle gathering has been a focus for regional tourism. The Fraser Valley Bald Eagle Festival was previously held annually in Harrison Mills. Tourism Harrison later rebranded the period from October to January as 'Season of the Wild' to highlight the area's diverse wildlife.