Alaska Highway travellers should note the chance of running into a highway closure west of Tok, Alaska because of a forest fire, says a state fire information officer.

Pete Buist said today the highway was closed for a couple of hours Wednesday night. It was eventually reopened and was still open late this morning in advance of peak burning conditions this afternoon.

"What we are saying is travellers should expect intermittent closures, and pilot car escorts,” he said. "We call it learning to love Tok.”

Buist noted the Eagle Trail fire 18 kilometres west of the Tok junction prompted a mandatory evacuation order for the 200 or 300 residents of Tanacross and the Eagle subdivision.

The Yukon's two air tanker groups, the DC-6 group stationed in Whitehorse and the three Firecats in Dawson City, provided support for Alaska firefighters last night.

Both groups were dispatched at around 6:30 p.m. and were on the Eagle Trail fire until 1 a.m. today, reloading and refuelling out of Dawson, where they returned this morning.

Whitehorse fire information officer George Maratos said the Yukon would be providing air support this afternoon, but with only group at a time to ensure there's air support available here as fire conditions in the Yukon become more volatile.

As one group returns to Dawson from the Alaska fire, the other will depart and so on, he explained.

Maratos said the fire danger rating has jumped up across the territory, and sunny and hot conditions are expected to persist.

No action is being taken on the four fires burning in the Carmacks and Dawson regions because they are all in the wilderness zones, Maratos said.

He said aerial detection flights were scheduled today to check on reports of smoke and the suspicion of new fires in the Carmacks and Old Crow districts.

The danger rating is extreme in the Whitehorse, Ross River, Mayo, Carmacks and Beaver Creek regions; high in Dawson, Haines Junction and Teslin; and moderate in Old Crow.

"Our fire season is here but the conditions are much more extreme than they were at this time last year,” Maratos said.

Buist said conditions in the western half of Alaska are also extreme, and the state picked up 20 new starts Wednesday.

Yesterday's fire, he said, quickly jumped from about 2.5 hectares, when it was reported by a private pilot, to 690 hectares, and this morning, it was estimated at 810.

"And the fires have been burning into the evening moreso than they usually are for this time of the year,” he said. "Especially with our Memorial Day coming on, when a lot of people want to go to the woods and catch a fish; it's a good time to keep a close eye on campfires.”

Buist said a senior forest fire management team was scheduled to be on the Eagle Trail fire today, and forestry officials have called on all available resources to help battle the blaze.

Two crews of 20 firefighters responded Wednesday.