As a consequence, the sediments at the bottom of Lower Mystic Lake accumulate in annual layers (or varves) that have been nearly undisturbed for a thousand years.

In the case of Lower Mystic Lake, the varves have been used by Mark Besonen and his collaborators to study the historical incidence of hurricanes.

[6][7][8] The eastern shore of the lakes is part of the Mystic River Reservation managed by the Massachusetts Department of Conservation and Recreation.

[9] In the 1600s, the Squaw Sachem of Mistick, who deeded much of the land in Greater Boston to settlers, resided near the Mystics Lakes.

[10] An indigenous burial site from the 1600s, possibly of sachems Nanepashemet or Montowompate, was discovered in 1862 just east of the Mystic lakes and was memorialized as Sagamore Park.