On Halloween day of 1991, a North Atlantic hurricane cut a 100-foot-wide opening in the narrow barrier dune at Ballston Beach, and seawater surged into the freshwater marshes of the upper Pamet River, eventually reaching Route 6 and briefly turning the end of Cape Cod into an island. Local resident Andy Shot watched the breach occur after sunset and recalled water smashing through the dune like a wall even in dim light. Such overwashes were not unique in the past century, and each time the barrier dune rebuilt itself. Today, sand fencing and use of established footpaths to the beach help stabilize the dune. Most of the sediment is moving northward, building up the Provincetown hook and offshore bars, so the tip of Cape Cod is actually growing, even as Cape Cod's outer beach is eroding at a long-term average rate of 2.6 feet per year. When Henry David Thoreau walked these beaches in the mid 1800s, he wrote that the sea played with land while holding a sand bar in its mouth, and following his footsteps today would place a person several hundred feet out at sea.