This species of milkvetch is narrowly distributed only in Washington County, Utah. In 2006 it was reported that there are just over 4,200 individuals in existence, 75% of which are within the boundaries of Zion National Park. This extremely sparse distribution earned Shivwits milkvetch the status as an endangered species on September 28, 2001. In addition to other conservation efforts, Zion’s resource management team has worked to propagate this species in the native plant nursery. Although these plants are threatened by human activities and invasive exotic plants, their population has increased in the past decade. This increase is strongly linked to precipitation and other climatic factors. The growing population has also benefited from the 2,151 acres of protected habitat set aside for this species and speaks to the success of Zion’s conservation efforts.
This specimen was collected by Stan Welsh of Brigham Young University. Welsh collected 5 new species for the Zion flora from 1981-1984, including the holotype of Carex haysii with S.L. Clark and Larry Hays in 1984.