The first elk was killed near present-day Omaha on Aug. 1, 1804, William Clark's 34th birthday. The first buffalo was taken Aug. 23, 1804, near what is now Vermillion, S.Dak., where Meriwether Lewis saw vast herds of the animals. John Colter shot the first mule deer on Sept. 17, 1804, also in South Dakota. The first grizzly bear was killed at the mouth of the Yellowstone River on May 5, 1805. It took Clark and George Drouillard 10 shots to put the bruin down for keeps.