of rodents like the beaver, hoary marmot and pika are also present. Ten species of bats have been documented. The grey wolf is listed as an endangered species, while the grizzly bear is listed as threatened. North Cascade National Park has management plans in place to return grizzly bears to the park but not wolves, as the latter is seen as likely to reestablish themselves naturally over time. The park is a prime habitat for grizzly bear, but the species was extirpated from the region by 1860. Only two grizzly bear sightings occurred in the decade before 2015, and these were outside the park boundary in Canada. In 1991, a decision was reached by the Interagency Grizzly Bear Committee, a US Government land management agency committee, to make efforts to restore self-sustaining populations of grizzlies in the North Cascades region, which included the national park and surrounding national forests. In 1997, the North Cascades region was added to the National Grizzly Bear Recovery Plan; by 2017, the environmental impact statement for grizzly bear restoration was still in the public comment stage. Various action plans had been proposed to reestablish a self-sustaining population of 200 grizzlies in the region. 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. More than 200 species of birds that pass through or use the park as a breeding ground have been recorded. These bird species include both golden and bald eagle as well as northern spotted owl, harlequin duck, Clark's nutcracker, trumpeter swan and