Leptoconops Skuse and Culicoides Latreille were collected using light or carbon dioxide baited suction traps in Grand County, Utah, 1999 through 2003 and in Garfield County, Utah, in 2003. Three species of Leptoconops and 38 species of Culicoides were collected. New Utah records included Leptoconops sublettei Clastrier and Wirth, Culicoides lahontan Wirth and Blanton, byersi Atchley, hinmani Khalaf, sitiens Wirth and Hubert, erikae Atchley and Wirth, inyoensis Wirth and Blanton, luglani Jones and Wirth, californiensis Wirth and Blanton, calexicanus Wirth and Rowley, reevesi Wirth, brookmani Wirth, bottimeri Wirth, owyheensis Jones and Wirth, kibunensis Tokunaga, and multidentatus Atchley and Wirth. Eight undescribed Culicoides species were identified: 1 in the subgenus Culicoides Latreille, 1 in the subgenus Diphaomyia Vargas, 1 in the palmerae group, 3 in the piliferus group, species 113 of subgenus Monoculicoides Khalaf, and 1 in the subgenus Selfia Khalaf. In addition, evidence was found for placing multidentatus into the subgenus Wirthomyia Vargas as a junior synonym of bottimeri.