Images are unavailable offline.

The Canadian Press

A wildfire just south of the Canada-U.S. border in Montana has triggered an evacuation alert for all of Waterton Lakes National Park.

Parks Canada says in a release that the fire is in Glacier National Park, about 5 kilometres south of the Waterton townsite in the Boundary Creek Valley.

The department says staff are monitoring as it approaches Upper Waterton Lake.

Story continues below advertisement

All trails and waterbodies in Waterton are closed, but highways and the townsite remain open.

Visitors and residents are being advised to prepare to evacuate on short notice.

Waterton was devastated by a forest fire last fall that consumed more than 190 square kilometres of forest, including about 80 per cent of the park’s popular hiking trails.