Founded in 1977, Extra Space Storage is a real estate investment trust based in Utah. The company maintains regional offices in California, Connecticut, Florida, Maryland, Massachusetts, New Jersey, New York and Texas. It is one of the largest developers, acquirers and operators of self-storage properties in the United States. Extra Space Storage owns and manages more than 600 properties in over 30 U.S. states. The company has nearly 190 wholly owned properties. It also handles properties through joint ventures and unaffiliated third parties. Extra Space Storage has developed and acquired approximately 700 facilities. The company s more than 460,000 units are rented by over 330,000 individual tenants. It also offers boxes and locks.