Meriwether Lewis, Captain Assistant to Thomas Jefferson, avid student, expedition leader	William Clark, Captain Lewis’s former commanding officer, expedition coleader	John Ordway, Sergeant Journal writer (in case Lewis and Clark lose theirs’)	George Drouillard Interpreter, hunter, skilled woodsman	York Slave and lifelong companion of Clark	Pierre Cruzatte, Private Riverman, expert fiddle-player	Seaman Lewis’s pet, a 150-pound (68-kilogram) Newfoundland dog	Field brothers, Privates Joseph and Reubin, hard-working Kentucky men	John Shields, Private Oldest of the party at 35, a blacksmith and gunsmith	George Shannon, Private Youngest of the party, about 16