Traces ...

Somewhere down in that river is a Nissan 4x4.

The driver just kept going at the end of the Rimrock Straight, just north of the Awakino Gorge tunnel.

The Nissan was airborne till it hit the water after going end over end.

You can see the path he took, clipping the end of the chevron sign.

Apparently he had been trained as a rig worker to escape from a ditched helicopter.

It saved his life.

Recovery is going to be a bit of a mission, and will probably involve a diver and a crane

You can also see how easy it would be to "go missing".

The only real indication that something is amiss is the damage to the sign.