 Some counts put the number of crashes in the triangle at 2,000, including millionaire and record-breaking flyer Steve Fossett.Hypotheses that the crashes are related in some way to the United States Air Force's Area 51, or to the activities of extra-terrestrial aliens, have no evidence to support them.The Sierra Nevada is divided into a number of biotic zones, each of which is defined by its climate and supports a number of interdependent species.