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.
Middle Eocene (Bridger for mation).
The Bridger stage, when deposition was in progress in the -\Vind River basin, north of the mountain of that name, and in the basin of Green river.
The strange phenomena of this region were known to some of the Indians; they were discovered by John Colter, a member of the Lewis and Clark expedition, in 1807; the region was visited by James Bridger before 1840; an account of the geysers was published at Nauvoo, Illinois, in The Wasp, a Mormon paper, in 1842; Captain W.
A second group is typified by Palaeosyops, of the Bridger Eocene of North America; P. paludosus being an animal about the size of a tapir.
On the other hand, Palaeosyops is connected with Titanotherium by means of Telmatotherium of the upper Bridger and Washakia Eocene, a larger animal, with a longer and flatter skull, showing rudiments of horn-cores, only two pairs of lower incisors, and a general approximation in dental character to Titanotherium.
Mormon migration passed along the trail in 1847-1849, and in 1853 fifty-five Mormons settled on Green river at the trading post of James Bridger, which they purchased and named Fort Supply.
Almost half a century later, in the winter of 1824-25, James Bridger, a trapper, discovered the Great Salt Lake while seeking the source of the Bear river.
"Jim" Bridger, a famous mountaineer and scout, saw the lake in 1824, apparently before any other white man.