Wolverines are one of the rarest and most elusive mammals in North America. They are seldom sighted in the park, both due to the limited numbers of the species and the habitats they prefer, which are snowy high-altitude regions far removed from human encroachment. Approximately nine wolverines were captured in the national forest east of the park and fitted with transmitters that were tracked by Argos satellite telemetry. Four of the wolverines frequented the southern sections of North Cascades National Park, and of those, two spent the majority of their time there; researchers were unable to determine if these study animals had reproduced in the park. A warming climate may impact any wolverine recovery efforts implemented due to the loss of snow cover this species needs to reproduce. Research indicates that wolverines den in deep snow at least deep that lasts well into May, and as climate warms, these regions are becoming less common, especially in the lower 48 states.