Surveys of human intestinal protozoa in the United States have been confined mostly to Eastern sections of the country and to the Pacific coast. There has been little work done concerning these parasites in western mountain states, and no previous surveys have been made of these organisms in the Intermountain West. It is important that the kinds oand numbers of these parasitic protozoa be dtermined for this locality; and it is only through surveys that the harmful, as well as the commensal, intestinal protozoa can be determined and treated. In 1933, teh city of Chicago experienced a general epidemic of amoebic dysentry, believed to be caused by a Endameba histolytica carrier. The seriousness of this epidmic led to the realization that the amoebic dysentary of the tropics could occur in tempearte regions. It is one of the purposes of surveys to recognized the incidence of pathogenic protozoa, with the purpose of averting possible epidemics of dysentary, diarrhea and other minor intestinal disturbances.