The Usotannai River, known as a river of placer gold, in autumn, salmon (also known as: chum salmon, autumn salmon) and pink salmon ascend upstream for spawning.
The abundant spring water seeping out from Mt. Shumon, 761m above sea level, is indispensable for the spawning of salmon and trout and the growth of their eggs, and many fish return to their home river.
The "hotchare" (carcasses) of salmon and trout that have finished spawning, exhausted their strength, and died, are utilized by brown bears, foxes, crows, gulls, etc., as important nutrition that brings rich blessings to the forest.
Especially when November begins, Steller's sea eagles and white-tailed eagles that had spent the summer in Russia, Sakhalin, etc., migrate here and gather, aiming for the hotchare that have been cold-preserved in the river.

The peak of eagles is in mid-December, and in abundant years, it becomes 400-500 birds. Many eagles take a rest, and the "eagle-bearing tree," where 50-60 eagles perch on a single tree, is also one of the attractions of this region.
From January onwards, the numbers decrease, and it is believed that they migrate towards the Doto (Eastern Hokkaido) area.

In the region, they are carefully watched over as the "Forest of Steller's Sea Eagles." To visitors, we request observation while observing manners.
Especially for photography, some people are seen entering grasslands, riparian forests, etc., and trying to approach the eagles by walking. Please cooperate in creating an environment where eagles can rest safely.
Also, dangerous situations have also come to be seen, such as long-term roadside parking on roads and photography with tripods on bridges. There is also snow accumulation and frozen road surfaces, and even one car is obstructing traffic.
When observing, please stop your car at the parking lot of the "Usotan Life Improvement Center" and observe and photograph, prioritizing the safety of your surroundings and yourself.