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.