Waramaug is the name of an Indian chief of the Wyantenock tribe who had hunting grounds near falls on the Housatonic River, now referred to as 'Lover's Leap', in the town of New Milford. Chief Waramaug and his followers wintered in the area now covered by Lake Lillinonah, which was later created by damming the Housatonic, and made Lake Waramaug their summer residence.

The land comprising the park, consisting of approximately 95 acres, was purchased by the State in 1920.