An intensive search has failed to find a tramper who went missing in "extremely difficult" terrain in Mt Aspiring National Park last night.
Two volunteer search and rescue teams have returned to the Wanaka's search and rescue base after a day-long search of a difficult gorge above the 'Jumboland' area in the upper reaches of the Wilkin River.
The missing man, whose name has not been released, was last seen at 6.30pm yesterday, when he parted with other members of his party to try to negotiate the gorge as a shortcut back to their campsite.
Wanaka police Search and Rescue coordinator Sergeant Aaron Nicholson said a river rescue team and bush search team had looked for the man through the day, while an aerial search also took place.
Searchers were confident the man had not gone beyond the area of the gorge and the flats directly below it, he said.
"The terrain in this area is extremely difficult and we have obvious concerns for his safety," Mr Nicholson said.
"We had hoped to find him, perhaps injured, in the gorge area but this has not been the case."
The teams would be thoroughly debriefed before deciding on the next steps to take, Mr Nicholson said.