During 6 years of small mammal trapping on Konza Prairie Research Natural Area, Kansas, we documented long-distance movements (defined as movements > 300 m) for 17 western harvest mice (Reithrodontomys megalotis). Linear distance moved ranged from 375 to 3200 m (median=600 m; mean=1049m) for all individuals. Males moved significantly farther, but not more often than females. Sixteen of the 17 animals that moved were adults and included reproductively active individuals. Although < 2% of the more than 1400 R. megalotis we captured moved > 300 m, the actual percentage should be much higher since our trapping efforts were limited in space and time. Since long-distance movements of individuals may have a marked effect on the genetic, social and demographic characteristics of populations, future studies of small mammals should be designed to better assess the influence of these movements on local populations