CHINCOTEAGUE, Va. (WAVY) — An online threat has been made against the 100th anniversary of the Chincoteague Pony Swim, a summer event that draws thousands to the small Accomack County town each year. 99th annual Pony Swim on Chincoteague draws thousands Chincoteague Mayor Denise Bowden, flanked by town Police Chief Tyler Greenley and another town officer, made the announcement about the online threat Friday morning. "We wanted to let the residents and visitors know that the town of Chincoteague has been made aware of a recent online threat involving the 100th anniversary of our world-famous pony penning festivities," Bowden said. "The security of our residents and visitors is always a priority of our pre-planning events, and this year's anniversary is no exception. And while the threat is under investigation, town officials are taking advantage of the enormous resources available to ensure a safe and enjoyable event for residents and visitors." Bowden called for people to report any suspicious activities or people to the town police department. The pony swim is world famous thanks to Marguerite Henry's 1947 book, "Misty of Chincoteague," which was also made into a movie. The Beebe Ranch in the book, where Misty lived and rode out the famous Ash Wednesday storm of 1962, is being restored after a major fundraising push. This year's 100th anniversary of the pony swim and auction is scheduled for July 30-31. The pony swim is hosted by the Chincoteague Fire Department. The pony swim takes place on Wednesday and a pony auction Thursday. For the pony swim, a group known as the Saltwater Cowboys rounds up feral Chincoteague ponies from Assateague Island and drive them across the Assateague Channel to Veteran's Memorial Park on Chincoteague Island. Once there, the Saltwater Cowboys herd the ponies to pens on the Chincoteague Carnival grounds, where some of the foals are auctioned off on the Thursday of the event.