Crupina vulgaris, crupina, a member of the Compositae family, is a recently introduced threat to the rangelands of Idaho. It is a competitive winter annual which, when established, develops nearly solid stands to the exclusion of desirable forage species. It was demonstrated by field trials that fall and spring application of picloram, glyphosate, dicamba, and 2,4-D (amine) were effective in greatly reducing or eliminating crupina for 2 years. Once crupina was removed by this effective management tool, desirable forage species replaced the unpalatable crupina.