The island is a part of the Hamonasset-Ledyard Moraine and was formed as glaciers retreated at the end of the last ice age. The Wisconsin glaciation formed drumlins in Milford: Clark, Burwell, Eels, Bryan and Merwin hills.Skehan, James W., Roadside Geology of Connecticut and Rhode Island, p 218, Missoula, Montana: Mountain Press Publishing Co., 2008,
The island is a part of the Hamonasset-Ledyard Moraine and was formed as glaciers retreated at the end of the last ice age. The Wisconsin glaciation formed drumlins in Milford Clark, Burwell, Eels, Bryan and Merwin hills.Skehan James W., Roadside Geology of Connecticut and Rhode Island, p 218, Missoula, Montana: Mountain Press Publishing Co., 2008,