A ground and air search has found a man missing in remote bush in the Pilbara.

The 51-year-old man was quad bike riding with three friends at the Fortescue River yesterday before deciding to return to Pannawonica.

He became separated from the group and failed to arrive in the town.

He was reported missing five hours later just before 9:00 pm last night.

SES volunteers from Karratha, Rio Tinto officers and local police took part in the search, and a helicopter was sent out from Pannawonica with SES air observers on board.

Sergeant Tony Di Giuseppe says they widened the area after the initial search did not find the man.

"It's believed that they were at an area known to some people as Swan Lake," he said.

"We've had a search team go to that area and there [was] no sign of him there."

The missing rider was spotted from the air about midday next to his bike.

He was approximately 12 kilometres east from where he was last seen.

Police say his bike had broken down.

The rider has been taken by helicopter to Pannawonica where he will be checked out at the local medical centre.

Sergeant Di Giuseppe says the terrain is inhospitable.

"It's accessible by basically trail bike or quad bike only," he said.

"A four wheel drive will get through there but from what I understand it's slow going and 20 to 30 kilometres an hour."

He says the man had little with him.

"We understand the only things he had with him was an esky full of ice on the back of a trailer," he said.

"Apart from that, according to his friends all else he had was a packet of cigarettes and a cigarette lighter."

In June last year, a 24-year old man went missing after quad biking in the same area.

He was found healthy but cold after spending the night in bushland in just board shorts and thongs.