Abstract
225 elk calves were tagged with plastic markers in 1949-51. Observations suggested definite migration routes. A study of horsefly populations suggested an inverse relationship between fly and elk numbers. Large numbers of elk did not arrive on the summer ranges until the vegetation was well developed. Parturition may have been an important factor governing the upward movement of the cows. Snow was apparently not a factor in retarding upward movement during the spring of 1951.