Search efforts will continue overnight for two trampers missing in the Tasman district, with a large drone deployed to create a heat map of the entire valley system.

Locals Jessica O'Connor and Dion Reynolds, both aged 23, set off near the Anatori River carpark on May 9 and have yet to return.

Senior Constable David Cogger, the officer in charge of the search and rescue mission, told NZME that three groups scoured the river catchment area today for any sign of the missing pair.

"We have been searching from the river mouth up into the high country," Cogger said.

Advertisement

A dog team accompanied one of those search teams, he added.

"We have had numerous footprints and numerous clues but nothing concrete - or nothing that is definite at this stage."

But Cogger said they had been "very keyed in" on tracing the pair's movements.

On May 12, at 16 minutes past midday there was a text sent by O'Connor saying she was "safe and happy" in the bush, he said.

A large team had also been speaking to members of the public who had been camping at Nikau Point, as there had been a large gathering there before the pair headed into the mountains.

O'Connor, who worked at Abel Tasman Kayaks, knew the area well.

"They were last seen with big packs consistent with having a lot of food onboard, good gear," Cogger said.

That combined with the qualifications and experience O'Connor had "put her in good stead".

Advertisement

Reynolds was also a competent outdoors person, he said.

Cogger said the weather had been good with no rain since May 3 - "rivers are very low".

Searchers will tomorrow use the heat map to help focus the efforts on land and from above with a helicopter.

It was historically a large gold mining area, with active gold claims so there has been a lot of earth moving, but no actual known hazards, he said.

"We don't know of anything untoward or of concern to the searchers or to Dion and Jess in that environment."

Mountain Safety Council chief executive Mike Daisley said the area was suited for very experienced trampers.

Advertisement

"It is a beautiful part of the countryside. There are lots of old ruins, old mining ruins and things to look at. There are a lot of nice gorges.

"But the environment is really really harsh. There are not a lot of tracks and the tracks aren't particularly well used."

Good navigational skills and survival skills were needed, he said.

"It was by no means really high mountains or anything, but it is really dense bush."