In 1909, workers poured the first concrete for the Panama Canal at a lock site at Gatun. Finishing all the locks there took nearly four years. A dam holds back the artificial Gatun Lake to supply water for the locks. The Gatun gate was closed on 27 Jun 1913, allowing Gatun Lake to fill to its planned depth. A few months later, on 26 Sep 1913, the tugboat Gatun made a trial run through the Gatun Locks. The control panel was not ready for the event, so the locks were operated manually. Everything worked perfectly. The Panama Canal crosses the Isthmus of Panama, joining the Atlantic and Pacific Oceans. Built 1904-14, it is only half the length of the Suez Canal. Unlike the Suez, the Panama Canal uses locks to raise and lower ships. Path Between The Seas: The Creation of the Panama Canal, by David McCullough. - book suggestion.