The Gatun Dam is a large earthen dam across the Chagres River in Panama, near the town of Gatun. The dam, constructed between 1907 and 1913, is a crucial element of the Panama Canal; it impounds the artificial Gatun Lake, which in turn carries ships for 33 kilometres (21 mi) of their transit across the Isthmus of Panama. In addition, a hydro-electric generating station at the dam generates electricity which is used to operate the locks and other equipment in the canal.