Search continues for Cleo Smith, 4, missing from family's tent at campsite north of Carnarvon

A search is underway for Cleo Smith, 4, in WA's north-west.

Emergency services are continuing to search for a four-year-old girl missing from a campsite in Western Australia's north-west since Saturday.

Cleo Smith was last seen at 1:30am on Saturday in her family's tent at the Blowholes Shacks campsite in Macleod.

Police said her family had realised she was missing when they woke at 6:00am.

The campsite is close to the blowholes at Point Quobba, about 75 kilometres north of Carnarvon by road and about 875 kilometres north of Perth.

Cleo Smith, 4, was last seen in her family's tent at a campsite north of Carnarvon on Saturday. (Supplied: WA Police)

An air, land and sea search was launched over the weekend, with state emergency service (SES) crews from Carnarvon, Shark Bay, Kalbarri and Geraldton joining police. 

In total, 22 SES volunteers joined the search along with community volunteers, with helicopters, drones and an Australian Maritime Safety Authority (AMSA) jet providing aerial support.

Marine search and rescue volunteers and fisheries officers have also been searching nearby waters.

Detectives from Perth, Carnarvon and Geraldton have been examining the area, along with forensics officers from Perth.

Emergency workers have been scouring the region for the four-year-old. (ABC News: Chris Lewis)

Police 'heartened' by information from public

Inspector Jon Munday said police had gathered a lot of information and were "not ruling anything out" at this stage.

"We're really throwing everything we can at this search in these initial stages," he said.

Police are coordinating the search for Cleo near the blowholes campsite. (Supplied)

He said the family, who live in Carnarvon, had arrived at the blowholes on Friday for a weekend camping trip.

"The parents did have an interaction with Cleo in the early hours of the morning," he said.

"Needless to say, we just hold grave concerns for Cleo's safety."

Inspector Munday said information about Cleo's disappearance had been distributed to roadhouses and other locations in a 1,000-kilometre radius from the campsite.

Dash cam and CCTV footage from roadhouses was being examined by police for any potential leads.

"We've been really heartened by the amount of information that's coming from the public," he added.

"At this point in time, we don't have any answers as to where Cleo is.

Inspector Munday said the environment was fairly harsh, but the weather was conducive to "surviving the elements".

"We are fairly confident that if Cleo is around here, we will find her," he said.

Cleo was last seen wearing a pink and purple one-piece sleepsuit with a blue-and-yellow pattern.

Anyone with information is asked to contact police immediately on 131 444.

Marine search and rescue volunteers and fisheries officers have been searching nearby waters for missing four-year-old Cleo Smith. (ABC News: Chris Lewis)