Some actually den on islands in the lake, a behavior noted nowhere else on Earth. On the coast, Puale Bay provides haul-out beaches for thousands of Stellar sea lions and other sea mammals. Wolves, moose, and members of a caribou herd numbering 15,000 are commonly sighted. Becharof shows the scars of recent volcanic activity. In 1977, violent eruptions formed the shallow, broad, low-rimmed craters of Ukinrek Maars, also near the lake.
Hunters score an unusually high success rate with bears and caribou.
Wildlife observers and photographers are common human visitors. Bear precautions are in order. Summer temperatures may rise into the 70s. Rainfall has reached 160 inches per year on the Pacific side of the Alaska Peninsula.