Somerset Island, 24 786 km2, ninth-largest island in the ARCTIC ARCHIPELAGO. Its western part is on Precambrian bedrock, reaching an elevation of 503 m, but the larger part is an elevated plateau of sedimentary rocks. Vegetation is scant, except in some depressions and lowlands where Peary caribou are common. Muskoxen are making a comeback after having been decimated by whalers around the turn of the century. Hundreds of thousands of birds nest on the sheer cliffs of Prince Leopold I, off the NE tip of Somerset. The island was named by Lt W.E. PARRY, who discovered it in 1819, after the county in England.