Blood smears of blood collected in 1971 and 1972 from 291 Canada geese at Malheur National Wildlife Refuge were examined to determine the incidence of the avian malarial parasite, Leucocytozoon simondi. No parasites were found. Absence of blood parasites suggests that birds using migration routes to the north and northeast of Malheur are free of the disease. The Leucocytozoon infections known in California waterfowl may be attributable to sources within the flyway east or northeast of California, to infected birds crossing over from other flyways, or abnormal conditions in the molting grounds of sub-adult and non-nesting birds where major flyways converge in northcentral Canada.