 Several species have been reintroduced to the gorge . White @-@ tailed deer were imported from Michigan and released throughout Pennsylvania to reestablish what had once been a thriving population . The current population of deer in Pennsylvania are descended from the original stock introduced since 1906 , after the lumbermen had moved out of the area . The deer population has grown so much that today they exceed their carrying capacity in many areas . River otters were successfully reintroduced in 1983 and now breed in the gorge . Despite the otters ' diet of 5 percent trout , some anglers fear the animals would deplete the game fish in the gorge . 
