Lewis and Clark Expidition By facebooker_100000178898864 Period: May 1, 1804 to Sep 1, 1806 Lewis and Clark Expidition events May 24, 1804 Lewis and Clark expidition officially begins Period: Nov 5, 1804 to Mar 23, 1806 Lewis and Clark Nov 1, 1805 They reached the pacific ocean in present day oregan They reached the pacific ocean in present day oregan Nov 1, 1806 Arrived home