ABSTRACT
The Rocky Mountain mule deer is found in the western US Most herds are migratory. They spend the summer in the higher elevations, but deep snows during winter may force them to move to winter ranges in the lower elevations where herds are relatively concentrated. In mountainous terrain where some quadrats have large elevation changes from one corner to another or where erratic winds are frequently encountered in canyons, a helicopter with sufficient power and maneuverability is imperative. During the perimeter flight, count only deer inside the quadrat. Upon completion of the perimeter flight, the quadrat was gridded back and forth along contours at an altitude of 50 to 100 ft and ground speed of 35 to 45 mi/hr until the quadrat was covered. When deer were observed, the pilot left the grid pattern and flew directly to them; they were counted before the group scattered. The pilot then returned to his former position on the grid.
