Many of them ended up in the Tewa Valley of New Mexico to the South through which the Rio Grande River runs, something that new research has confirmed with evidence like the genetics of turkey bones, which is expanded upon in an article for the High Country News.
In part, this was driven by climate.
But, archaeological evidence and the oral tradition also suggests that there may have been a radical change in the social, political and economic organization of the migrants.
The Mesa Verde civilization was economically organized by household and was riddled with intracommunity strife that may have been along the lines of disputes between the haves and the have nots in the society.
But, late in Mesa Verde's development, a new more community oriented society was developed around a community about six miles away now called "Yucca House" in a national monument, that put a public square rather than family specific kivas at the center of the community and was more egalitarian and communal. This late site near Mesa Verde appears to have provided the social model for the migrants communities new homes in the Teva Valley that consciously rejected much of the old material culture and architectural style of the Mesa Verde civilization that failed when placed under stress.