It is a poorly known fact that camels originated in North America, where they also underwent most of their evolution.
Western camels were confined to North America, having been most abundant in the western United States, southwestern Canada and central Mexico during the last part of the ice age (about 600 000 to 10 000 years ago). They probably reached Yukon and Alaska by migrating northward via dry terrain on the eastern flanks of the Rocky Mountains during a relatively warm phase of the Pleistocene Epoch some 50 000 years ago. They died out there about 20 000 years ago. Tracks of this species have been preserved in 11 000-year-old sediments at a site near Cardston, Alberta.
How did they survive the northern winters? Modern camels are able to grow thick pelts under cold conditions. For example, travellers have encountered Bactrian camels (Camelus bactrianus) "plodding stoically through north-Asiatic blizzards".
The western camel probably looked like a large dromedary (Camelus dromedarius), but its limbs were about a fifth longer, its head was longer and narrower, and the face was flexed downward to a greater extent.
The western camel probably ate as much leaves, forbs (herbs other than grass) and fruits, as grass. This species seems to have been adapted to arid scrublands and grasslands.
Western-camel remains have been reported from at least 18 Paleoindian sites dating between about 12 600 and 10 000 years ago (when the species seems to have become extinct). Butchering of western camels is recorded at two sites in Wyoming, U.S.A.