A man is in a critical condition in Palmerston North Hospital after plunging 60m down a cliff at a central North Island Reserve.

Fire and Emergency central shift communications manager Carlos Dempsey said the man fell down a steep bank at the Vinegar Hill Domain, south of Hunterville, about 2am.

In what Dempsey said was a "dramatic and difficult" overnight rescue, fire crews and a rescue helicopter spent three hours in pitch darkness to find and reach the injured man who was in a spot on the sheer cliff face that was difficult to get to.

The helicopter was eventually able to winch the stricken man out of danger, Dempsey said.

"The person was about 60m down the bank and access was quite difficult," he said.

A St John spokeswoman said the man was flown to Palmerston North Hospital with critical injuries.

Dempsey said ambulance crews at the riverside domain asked for help to reach the injured man.

He said fire crews from Hunterville and Kimbolton and a specialist lines rescue team from Whanganui went to the domain off SH54 and

The Palmerston North-based rescue helicopter successfully winched the victim off the sheer river cliff face around 5am.