The other area is now the southwestern United State and northern Mexico. Over many years, as the weather warmed up and glaciers began to melt, the two groups of sheep moved around more, but they did not get together. Because these two groups lived apart for thousands of years in two very different places, their bodies and their behavior slowly became different, too. Thinhorns are smaller than bighorns. They are from the northern ice-free are.
Bighorns are from the southern ice-free area.
Thinhorn sheep have pale brown horns with a touch of yellow. The horns are lighter and skinnier than those of the bighorns. Dall's sheep are the ONLY white wild sheep in the world. They live in Alaska, Canada's Yukon, Northwest Territories, and far northwestern British Columbia. Stone's sheep are almost black, except for a white face, white inner leg, and white rump.