An active volcanic island, Bogoslof has undergone change as recently as 1993. A single rugged spire, Castle Rock, stands above the island's rocky beaches and black lava. As many as 90,000 murres, kittiwakes, puffins, and gulls nest here. A rookery of fur seals has grown in size, while a sea lion rookery that peaked with about 5,000 individuals has shrunk. North of Unalaska Island, Bogoslof is difficult to access and rarely seen except over the gunwales of passing fishing boats.
Winds blow almost constantly during cool foggy summers and mild foggy winters.
Although the Bering Sea does not freeze here, storms come often and remain long, violently hurling wind and waves against the barren shoreline. The few boats that do arrive find no anchorages, coming only at risk and with special permission of the refuge manager for scientific or educational purposes.