The purpose of this project was to determine the nonwinter and winter home ranges of porcupines in a mixed hardwood forest in northern New York and to monitor den activity to determine daily and seasonal changes in den use. Primarily, I a) measured the home range of three radio collared porcupines to determine seasonal and yearly variability; b) monitored den usage to determine time of day of peak activity, seasonal activity differences, and instances of den sharing; and c) observed sexual differences in home range and den usage.