The New South Wales Rural Fire Service [RFS] has issued an emergency warning for the blaze at Paddy's River, near Wingello, saying it had crossed the Hume Highway and was burning in an easterly direction towards Hanging Rock.
The Hume Highway is closed in both directions due to the fire, which is about 160km west of Sydney and east of Canberra.
Firefighters and aircraft including the Large Air Tanker are working to slow the spread of the fire.
Looks like one Caravanner is in for a lengthy stay.