Bolton’s Mysterious Roving Islands

by Hans DePold, town historian
(Published in the Bolton Community News, June 2004)

On Monday, Feb. 28, 1955, on page 4 of The Bridgeport Telegram, there appeared an article titled "Crane, Bulldozer Tear Apart Roving Island in Bolton Lakes." The action was taken under the supervision of the State Board of Fisheries and Game. The floating island had measured 125 feet long, 75 feet wide, and 7 feet thick. It had supported cedar trees (one 8 yards tall) that served as masts and sails to drive the island around Bolton Lake. It had become a favorite private spot for young Bolton boaters, explorers and lovers.

Bolton Lake was created in the mid-1800s as part of a system to provide waterpower to the mills of Willimantic before electricity, internal combustion motors, or even steam power. The prehistoric Mohegan tool-making site at Bolton's Cedar Swamp was submerged when the lake was created.

As darkness descended, factories would close shop and the lake outlet was closed, raising the water level. Then as daylight approached, the lake sluice gates would be opened, doubling the normal flow rate in the rivers powering Connecticut's industrial revolution. That was known as Connecticut ingenuity.

Bolton's roving islands were born when vegetation deposits created a layer of peat that had sufficient buoyancy to tear itself free from the bottom of the lake. Longtime lakeside resident Grant Davis noticed that they seemed to occur when the lake level changed. On occasion he's witnessed the lake giving birth and has had to raise his sailboat's dagger keel in those areas where infant roving islands were not yet fully surfaced. In the last 10 years he has seen one island about 7 yards across and a smaller one about 1 yard or more across. Native Americans called them "trembling earth," referring to the way they shook when walked upon.

Davis believes that lower lake levels decrease the overburden of the water that normally holds the peat down and compresses it. A lower lake level allows the peat to expand, increasing its buoyancy. Once part of the peat begins to tear away from the bottom, the water gets under it and there is no longer any overburden but just pure buoyancy force. Heavy soils drop away and a new roving island is born. Land plants like winterberry holly, highbush blueberry, arrowhead, fern, and broad-leafed cattail then take root and hold the island together. The island moves about with roots dangling downward like the tentacles of a large lake creature feeding beneath the surface. The islands may also be blown into shallow areas and can reattach for years.

In the rising evening mist, a roving island could be a haunting sight. They were primal forces silently creeping about the lake, obeying only natural laws of wind and water currents. As the Bolton Lake population grew, one very large roving island seemed to protest and sheared off more and more docks. Perhaps it had acquired some of the earth and spirit of the Native Americans interred beneath the lake. It would park itself wherever it pleased—it was just too bad if it chose your sandy beach as its new resting spot!

Soon this mother of all roving islands seemed to be friendless. No one had anything good to say about roving islands on February 28, 1955, when Bolton's largest recorded roving island trembled its last time and was laid to rest.