Buldir Island (also sometimes written Buldyr; Aleut: Idmaax) is a small island in the western Aleutian Islands of the U.S. state of Alaska. It lies midway between the Near Islands in the West and the Rat Islands in the East. It is the most westerly of the Aleutian Islands which formed as a result of volcanic activity in the late Quaternary or Recent times. The rocks from which the island formed are of two different ages with a considerable time gap. The rocks of the older dome are mainly olivine basalts and the younger dome consists of hornblende basalts and basaltic andesites. That this island is younger than some of the neighboring islands is also suggested by the fact that there are fewer species of flowering plant on this island.
Buldir Island was first sighted on October 28, 1741 by Vitus Bering during his exploration of the region. The island is small, with an area of just 7.4482 square miles (19.291 km2). It is 4.3 miles (6.9 km) long and 2.5 miles (4.0 km) wide. There was no human population reported by the 2000 census. The two major volcanoes on the island are the Buldir Volcano, which forms most of the island, and the East Cape Volcano, which forms the island's northeast section. Buldir Volcano is the taller, reaching 2,152 feet (656 m) in height, the highest point on the island. The coastlines along the island are often tall steep cliffs.
The island is home to 21 species of breeding seabirds, making it the most diverse seabird colony in the Northern Hemisphere. The island's colonies include crested auklets and least auklets, as well as puffins, storm petrels and other species. It is one of only four locations in the world where red-legged kittiwakes breed.
- Bergsland, K. (1994). Aleut Dictionary. Fairbanks: Alaska Native Language Center.
- Coats, Robert R. (1951). "Geology of Buldir Island, Aleutian Islands, Alaska" (PDF). Mineral Resources of Alaska. US Geological Survey. Retrieved 2013-12-13.
- Buldir Island: Block 1146, Census Tract 1, Aleutians West Census Area, Alaska United States Census Bureau