Terrifying wildfires have killed at least two people in Washington state as they continue to rip across more than 20,000 acres.

Governor Jay Inslee declared a state of emergency for Spokane County where the largest wildfire destroyed nearly 11,000 acres of land, razing nearly 200 buildings as thousands were evacuated.

The entire North Western state remains under an alert, while the largest parkland area - Mount Spokane State Park - has been closed off to the public, as has Interstate 90, as firefighters battle to contain the inferno.

The blaze - known as Gray Fire - started around midday Friday on the west side of Medical Lake around 15 miles west of Spokane. Washington State Department of Natural Resources warned the fire is still spreading.

In an update Sunday, the department warned the blaze was still '0%' contained despite the efforts of firefighters, and it was engulfing more land towards the southwest.

A grab from a TikTok video shows the Gray Fire burning in eastern Washington Saturday. The blaze has killed at least one person, and destroyed close to 200 structures

Another grab from the same video shows a classic Pacific Northwest backdrop of Douglas firs and water - but shrouded by smoke and flames

This map shows just how many fires are burning across eastern Washington and western Canada. All of Washington is currently under some sort of wildfire alert

This Washington state alert shows how the entire state is now under some sort of wildfire-related alert

This graphic shows the large swathe of Spokane Valley in Eastern Washington that has been warned to prepare for evacuation as wildfires continue to burn

'Still a lot of hazards within the burned areas.' a spokesperson for the department said. 'Natural gas lines venting off, trees coming down, etc.'

There are also 27 smaller wildfires raging over a combined 10,000 acres at scattered locations across the state.

Transport officials have said dense smoke is the biggest challenge for emergency services, because visibility is so bad they are not able to deploy air resources in many areas.

Huge plumes of smoke are growing over Spokane County, while fumes from the Canadian wildfires raging just beyond the northern border are compounding the issue.

Level three evacuation notices are in place in Spokane County and Ponderay County to the north - where a combined population of around 560,000 people live.

An eerie photo shows a road disappearing into yellowish-gray smoke caused by the fire

Meanwhile, the longest freeway in Washington state, the I90, has been shut off for more than 24 hours due to the fires and people are being advised to leave via alternative routes.

Washington Governor Jay Inslee said the fires are a result of climate change, and urged residents to 'be safe' by listening to emergency responders.

'As these fires rage in Spokane County we want to thank the first responders who are doing such tremendous work in a coordinated effort - thank them if you get a chance... We're going to continue to help in every way that we can.

'This is so troublesome, and there's a certain irony that I'm at a conference about how to fight climate change, and the fires are caused by this.

'Let's think of the people of Spokane and during the recovery as well - be safe.'

The air quality in Spokane County has reached an index of 349 - which is in the most extreme category of 'hazardous' to anyone who breathes the air.

A healthy AQI would fall within 0 to 50.