The owners of a series of huts at Donnelly River in the state's South West are preparing to defend their properties as a bushfire burns close to the remote area.
Two fires are burning in the region, one in the Donnelly River area and another near Burekup, both at watch-and-act level.
Department of Biodiversity, Conservation and Attractions duty officer Bruce Bone told the ABC on Monday afternoon favourable conditions were expected for both fires.
Mr Bone said the fire in the Donnelly River area had burnt about 6,500 hectares.
"We're about 95 per cent contained at the moment [for the Donnelly River fire], but it's not completely contained and controlled, hence the watch-and-act is still in place."
Deputy incident controller Craig Garrett said support had been offered to those who decided to remain.
"The fire may not reach them today because of the change of wind, that may eventuate tomorrow," he said.
"They understand they won't be able to traverse the river in that time and they may be there for the next couple of days until it's safe to come out."
Mr Garrett said fire crews had been working to protect the historic huts and were in regular radio communication with those who elected to stay.
"They have a defendable space around those structures and with the retardant drops and the other work we have been doing around the structures we believe they are in a good position.
Manjimup Shire president and hut owner Paul Omodei said there were 33 huts on the Nannup Shire side of the river and 10 huts on the Manjimup Shire side.
"There are about 30 guys down here, all equipped, all waiting, all being well briefed by the DBCA (Department of Biodiversity, Conservation and Attractions).
"Everyone is required to have firefighting equipment and the majority of the huts do, and those that haven't we will just have to cover for them."
Thousands of hectares burned
The Donnelly watch and act alert is in place for people in the vicinity of Donnelly River, including the Donnelly River huts and Boat Landing Road, from Scott Road in the north to Vasse Highway and Ritter Road in the Shire of Nannup and the Shire of Manjimup.
Access to the huts is by boat only.
The properties are about 12 kilometres down the river from Donnelly Boat Landing Road, which is currently closed.
More than 90 people are fighting the fire, with aerial support assisting ground crews.
Mr Omodei praised the efforts of fire crews.
"It's only really the actual firefighters that are under some kind of risk, the rest of us I think we all kind of know what to do."
Peter Casonato operates Donnelly River Cruises and said they had moved their boat to a safer location as the fire burns in the remote area.
"It's all in part of the D'Entrecasteaux National Park."
"There are very few access points in there, that's what is making it so difficult for guys fighting the fire."
Mr Casonato said there was a fire in the region 11 years ago.
Burekup fire jumps containment lines
A fire on the edge of the Wellington National Park was upgraded to a watch and act on Monday afternoon.
The warning is in place for people near the Coalfields Road (also known as Coalfields Highway), Wellington Dam Road, Henty Road, South Western Highway and Pile road in Burekup and Wellington National Park in the Shires of Dardanup, Colllie and Harvey.
"Overnight we are looking at moderate conditions and humidity," Mr Bone said.
