UPDATE 1PM: The site is being cleared and traffic is now getting through.
The Westpac Rescue Helicopter has taken a 26 year old female from Wingen to John Hunter Hospital suffering head and chest injuries after the accident on the highway this morning.
The patient was treated on scene by ASNSW paramedics and the Helicopter Critical Care Medical Team.
The patient is in a serious but stable condition.
The New England Highway is closed near Wingen after a serious accident.
Emergency services were called to the highway 10 kilometres from Wingen near Scone after a car hit a rock wall.
A female driver is being assessed at the scene for head injuries.
NSW Ambulance says she is in a critical condition.
The highway is currently closed in both direction so the Westpac Rescue Helicopter can land.
Motorists are advised to delay travel between Muswellbrook and Willow Tree, use an alternative route or allow plenty of extra travel time.
Police are on-site while traffic crews are attending.
Image credit: Grant Broadcasters/Jessica Rouse