Thomas Jefferson instructed Meriwether Lewis to take particular notice of "the animals of the country generally, & especially those not known in the U.S" (Jackson, item 47). Lewis took great pains to follow these instructions. Without the benefit of any formal training in zoology, Lewis collected, described, preserved, and sketched hundreds of animals. He even went to the trouble to send a live prairie dog to President Jefferson. Although a scientific volume of Lewis's animal descriptions was never compiled during his lifetime, his discoveries did help inform fur traders of the great abundance of animals in the west.