Several big environmental groups launched a drive on Tuesday to save California's newly-established Giant Sequoia National Monument, saying a lawsuit seeking to dismantle it would spell disaster for the world's oldest and largest trees. In papers filed in District Court in Washington D.C., the Sierra Club, the Earthjustice Legal Defense Fund and several other groups sought to intervene on the side of the monument, which former President Bill Clinton established under the Antiquities Act in April, 2000.