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)
Under the provisions of Article XII, the United States and Panama agreed to study jointly the feasibility of a sea-level canal and, if deemed necessary, to negotiate terms for its construction. Payments to Panama from the commission ("a just and equitable return on the national resources which it has dedicated to the . . . canal") were set forth in Article XIII. These included a fixed annuity of US$10 million, an annual contingency payment of up to US$10 million to be paid out of any commission profits, and US$0.30 per Panama Canal net ton of cargo that passed through the canal, paid out of canal tolls. The latter figure was to be periodically adjusted for inflation and was expected to net Panama between US$40 and US$70 million annually during the life of the treaty. In addition, Article III stipulated that Panama would receive a further US$10 million annually for services (police, fire protection, street cleaning, traffic management, and garbage collection) it would provide in the canal operating areas.