1984 |1 September 1995 |---- |style="text-align: left;"|Cristobal Junior-Senior High School |civil |school |data-sort-value="1 January 1990"| 1990 |1 September 1995 |---- |style="text-align: left;"|Chiva Chiva Antenna Farm (Foreign Broadcast Information Service) |military |communications |data-sort-value="1 January 1993"| 1993 |6 January 1998 |---- |style="text-align: left;"|Curundu Middle School |civil |school |1 August 1997 |15 September 1999 |---- |style="text-align: left;"|Piña Range (remainder) |military |training |30 June 1999 |1 July 1999 |---- |} * Enclaves are a subset of those areas that were categorized in the 1977 Panama Canal Treaty as "Military Area of Coordination", "Defense Site" and "Area Subject to Separate Bilateral Agreement". The map legends and color coding that are contained in the Panama Canal Treaty Annex provide visual corroborations of the treaty language. Postage stamps The Panama Canal Zone issued its own postage stamps from 1904 until October 25, 1978. During the early years, United States postage stamps overprinted "Canal Zone" were used. After a few years, accredited Canal Zone stamps were issued. After a transition period during which Panama took over the administration of postal service, Canal Zone stamps became invalid. The two-letter state abbreviation for mail sent to the Zone was CZ. Canal Zone Matches Damp Proof "Canal Zone Matches" were manufactured by Jönköpings Westra Tändsticksfabriks, Sweden expressly for the Panama Canal Company. Amateur radio Amateur radio licenses were issued by the United States Federal Communications Commission and carried the prefix KZ5, the initial 'K' indicating a station under American jurisdiction. The American Radio Relay League had a Canal Zone section, and the Canal Zone was considered an entity for purposes of the DX Century Club. Contacts with Canal Zone stations from before repatriation may still be counted for DXCC credit separate from Panama. The KZ5 amateur radio prefix has been issued to license operators since 1979 but today has no special meaning. See also Martyrs' Day (Panama) Panama Railway Rail transport in Panama Transcontinental Railroad#Panama List of former United States military installations in Panama List of Governors of Panama Canal Zone Postage stamps and postal history of the Canal Zone Naval Base Panama Canal Zone References Further reading and viewing Dimock, Marshall E. (1934) Government-operated enterprise in the Panama Canal Zone (University of Chicago Press) online. Donoghue, Michael E. (2014). Borderland on the Isthmus: Race, Culture, and the Struggle for the Canal Zone. Durham, NC: Duke University Press. Frenkel, Stephen. (2002) "Geographical representations of the 'Other': the landscape of the Panama