Wildlife sightings are plentiful around Petersburg. For bird lovers, eagles are regularly seen in the trees and on the beaches, as are over 240 species of birds that have been recorded on the 210-square-mile island. Mitkof Island is also home to healthy wolf, black bear, deer and moose populations. Sea lions and seals are often seen in the harbor and the surrounding waters. Orca whales can be spotted swimming off the shores of the island and, during the summer months, hundreds of humpback whales live and feed about 40 miles north of Petersburg where Frederick Sound joins with Stephens Passage. At the Petersburg Marine Mammal Center, located in the back of the Viking Travel Building, information and an interactive whale-learning display can be found. This display includes videos on whales and marine mammals of Southeast Alaska.