Isle Royale

Declared in 1940, this remote island out in Lake Superior has hosted since 1958 the longest continuous scientific study in the world of the predator-prey relationship between a single wolf population and a single moose population, naturally isolated from the mainland by the lake's freezing water. The study has documented complete cycles of population boom and collapse across more than sixty years, and in 2018 the National Park Service brought in new wolves from the mainland after the original pack all but collapsed from severe inbreeding.