Panama Canal Zone
The Panama Canal Zone () was an unincorporated territory of the United States from 1903 to 1979, centered on the Panama Canal and surrounded by the Republic of Panama. The zone consisted of the canal and an area generally extending on each side of the centerline, excluding Panama City and Colón, which otherwise would have been partly within the limits of the Zone. Its border spanned three of Panama's provinces. When reservoirs were created to assure a steady supply of water for the locks, those lakes were included within the Zone.
History of Panama (1977–present)
At the same ceremony in Washington, representatives of the United States and Panama signed a series of fourteen executive agreements associated with the treaties. These included two Agreements in Implementation of Articles III and IV of the Panama Canal Treaty that detailed provisions concerning operation, management, protection, and defense, outlined in the main treaty. Most importantly, these two agreements defined the areas to be held by the United States until 2000 to operate and defend the canal. These areas were distinguished from military areas to be used jointly by the United States and Panama until that time, military areas to be held initially by the United States but turned over to Panama before 2000, and areas that were turned over to Panama on October 1, 1979.