For instance: http://dstcentralregion.org/chapters/colorado-chapters/
There is a Tau Lambda chapter of DST that is listed as University of North Colorado. The Sorors at CSU are also listed as Tau Lambda chapter. This may be a core chapter.
http://www.baacc.colostate.edu/greek (this seems to include chapters that are city-wide and core chapters; and maybe some of this needs to be updated)