Utah State University Extension
What began in the 1950s as a small patch of weeds near a grain elevator in Juab County, turned into a serious environmental problem that impacts the state’s wildlife, grazing and tourist industries. In the early 1990s, it was estimated that squarrose knapweed infested nearly 200,000 acres of rangeland in central Utah.
Extension, USU, "Saving Utah's Landscape, Squarrose Knapweed" (2000). All Current Publications. Paper 1383.