U.S. fire managers get green light to operate in Waterton Lakes National Park

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The wildfire threatening Waterton Lakes National Park moved slightly north and east overnight Saturday, growing to about 860 hectares in size and reaching Boundary Creek in Glacier National Park.

The blaze remains entirely in Glacier National Park, which is on the U.S. side of the border.

The superintendent of Waterton Lakes National Park has granted authority for the American incident command team to operate on the Canadian side of the border, and they are working closely with Parks Canada staff, said spokesman John Stoesserin an update Sunday.

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Parks Canada used two helicopters Sunday morning to bucket water on a small spot fire on the south side of Boundary Creek, with U.S. National Park Service personnel monitoring the fire from the ground.

Fire managers will use the terrain of the area and avalanche slide path and the creek as a natural fire break in hopes of slowing the spread of the fire.

Crews also bucketedwater on a hot spot on the north side of Boundary Creek.

Sunday's forecast calledfor light showers in the afternoon with potential for 10 to 20 millimetres of rain by Monday.

"This weather change may limit fire spread but will not extinguish the fire," Stoesser said.

Winds from the southwest were also expected ahead of the rain.

Waterton Lakes National Park is closed because of the approaching fire, however businesses in the townsite remain open.

Anotherair quality statementwas issued for most of southwesternAlberta, warning smoke from B.C. wildfires could reduce air quality.

In Calgary, the air quality health index was expected to rise to 7 high risk by Sunday evening.

Hundreds of wildfires continue to burn across B.C. More than 945,000 hectares have been scorched in that province since April 1.

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With a file from CBC British Columbia