The Hanford Site is a 560 square mile complex established by the U.S. government in 1943 to produce plutonium for nuclear weapons, ultimately bringing an end to World War II.  Plutonium production activities continued after the war through 1991, at which point the site’s mission changed from plutonium production to environmental cleanup and restoration.  Production activities at the site resulted in a broad range of contaminated materials and facilities, including 57 million gallons of high level (i.e., highly-radioactive) nuclear waste in liquid and solid forms.  The high-level waste was stored as it was created, first in single-shell tanks built between 1943 and 1964, then in more-robust double-shell tanks constructed between 1968 and 1986.  The double-shell tanks have either exceeded or are expected to exceed their design life, and are managed under a comprehensive integrity management program.  This paper summarizes the history of the construction and operation of the Hanford Site’s waste storage tanks.