Extra Space Storage is a publicly traded real estate investment trust (REIT) that specializes in self-storage services. Headquartered in Salt Lake City, Utah, the company owns, operates, and manages over 2,000 self-storage facilities in 40 states, Washington D.C., and Puerto Rico, making it one of the largest self-storage providers in the United States. The company was founded by Kenneth M. Woolley in 1977 and went public in 2004.