Blowing Rocks Preserve began in 1969, when far-sighted and generous residents of Jupiter Island donated 73 acres of their island to the Conservancy.  The preserve was named for its rocky Anastasia limestone shoreline – the largest on the U.S. Atlantic coast. During extreme high tides and after winter storms, seas break against the rocks and force plumes of saltwater up to 50 feet skyward. It’s an impressive sight