It was reported at 10.40am today (Monday 13 May 2013) and involves two vehicles which collided on the A6108 prior to the bridge over the river Ure.
The drivers of both vehicles have both been airlifted to hospital with serious injuries.
The road is currently closed with diversion in place. The road is expected to remain closed for the next two hours while collision investigators examine the scene and the vehicles are recovered.
Any witnesses to the collision are asked to contact North Yorkshire Police on 101.