Whether or not Fremont peoples died out, were forced to move, or were integrated into Numic-speaking groups is unclear, and even the matter of the postulated Ute/Paiute/Shoshoni migration remains a matter of spirited debate. It appears that the sudden replacement of classic Fremont artifacts by different kinds of basketry, pottery, and art styles historically associated with Utah's contemporary native inhabitants suggests that Fremont peoples were, for the most part, pushed out of the region and were replaced rather than integrated into Numic-speaking groups. This interpretation is strengthened by the fact that the most recent Fremont or Fremont-like materials, dating to about 500 years ago, are found at the northern and easternmost fringes of the Fremont region, in the Douglas Creek area of northwestern Colorado and on the Snake River plain of southern Idaho--areas at maximum distance along the postulated migration route of Numic-speaking populations.
See: David B. Madsen, Exploring The Fremont (1989).
David B. Madsen