The Timeline of Glacial Melting and Sea Levels

When the ice sheet reached its maximum extents around 25,000 years ago, you could walk directly to Nova Scotia across the ice sheet that covered the Gulf of Maine. When the glacier finally retreated about 14,000 years ago, the sea flooded the interior of Maine submerging areas that are 300 feet above today’s sea level. In a process called isostatic rebound, over the the next ~1,000 years the sea retreated enough so that islands began appearing at the start of this trail, 222 feet above current sea levels. It took another ~1,000 years for the shoreline to drop to this spot (elevation – 166 feet). During this time, sea levels were also rising from the injection of water from the melting glacier, but not nearly as fast as the land was rebounding. Massive amounts of water was still locked in ice. Land extended unto the Gulf of Maine. Artifacts left by proto-indians have even been found on the ocean floor.