A small truck has collided with three motorbikes on the notorious Putty Road south-west of Singleton, killing one of the riders.
The accident happened at Howes Valley at around 1:20pm.
One of the riders died at the scene, a second rider was airlifted to hospital and the condition of the third is unknown.
The male truck driver was uninjured and has given mandatory blood tests.
The road remains closed in both directions.