Serpent Mounds operated as a provincial park, established in 1955 through a lease with the Hiawatha First Nation, of the Michi Saagiig (Mississauga Anishinaabeg).

In 1982, while operating as a provincial park the mounds were designated a National Historic Site, including East Sugar Island.

[1] From 1995 to 2009, Hiawatha First Nation operated the park privately, offering camping facilities, beach access on Rice Lake, a cultural center, and interpretive walks among the historic serpent and nearby mounds.

[2] Archaeological field work revealed that the construction and early occupation of the serpent mounds area occurred about 2000 years ago during the prehistoric Middle Woodland Period.

Significant items found inside the mounds, in addition to human remains, were shell disc beads, fossilized coral, fish bone hook, flint chips, copper foil beads, carved limestone, adze, and numerous types of animal bones.