The largest of all, Great Salt Lake, is maintained by the waters of the Wasatch and associated plateaus.
The typical Phenacodus primaevus, of the Lower or Wasatch Eocene of North America, was a relatively small ungulate, of slight build, with straight limbs each terminating in five complete toes, and walking in the digitigrade fashion of the modern tapir.
The family is represented in the Lower, or Wasatch, Eocene by Trigonolestes, in the Middle (Bridger) Eocene by Homacodon (Pantolestes), and in the Upper (Uinta) Eocene by Bunomeryx.
In the lower, or Wasatch, Eocene the group was represented by the still more primitive Lambdotherium.
The Wasatch Mountain range constitutes the eastern margin of the Great Basin in central and northern Utah, and resembles the true basin ranges in that it is formed by a great block of the earth's crust uptilted along a north-south fault-line.