It starts on the slopes of Mount Kosciuszko , Australia 's highest mountain . It gets its water from the eastern slopes of the Snowy Mountains in New South Wales , and then flows through the Snowy River National Park in Victoria and finally into Bass Strait . It originates on the slopes of Mount Kosciuszko , Australia 's highest mainland peak , draining the eastern slopes of the Snowy Mountains in New South Wales , before flowing through the Snowy River National Park in Victoria and emptying into Bass Strait .