It happened at about 11:50 p.m. in the area of Route 9G and Broadway.
Investigators say the students were among three people hit while they were walking northbound on 9G.
The victims have been identified as 20-year old Evelina Martin Brown of Seattle, Washington and 19-year old Sarah McCausland of Winnetka, Illinois.
The vehicle involved left the scene and was located by deputies a short time later, according to police.
Authorities say the driver charged is 63-year old Carol Boeck of Red Hook, N.Y.
She has been charged with Felony DWI (Class E Felony due to a prior conviction) and Vehicular Manslaughter 1st Degree, which is a Class C Felony.
Boeck was arraigned at the Village of Tivoli Court, and was remanded to the Dutchess County Jail in lieu of $50,000 cash bail or $100,000 bond.