The victims were driving in a Chevy Blazer that flipped on Seven Lakes Drive just before 9 a.m. and careened into Lake Tiorati.
The car was submerged in about 12 feet of water and the victims, believed to be an elderly couple, were pronounced dead at the scene.
Park roads in the area of the crash were closed by New York State Park Police.
This occurred inside Harriman State Park. It is the second-largest park in the parks system.