Parks Canada support personnel were evacuated from Waterton Lakes National Park on Sunday evening as officials expected the Kenow wildfire to intensify overnight.
Wildland and structural fire crews remain to continue preparations should flames threaten the townsite, about 270 kilometres south of Calgary.
A mobilized command centre is also being set up.
Officials said Sunday the fire had reached 9,400 hectares in size and had moved about five kilometres southeast along the Akamina Valley, about 20 kilometres from the Waterton townsite in southwestern Alberta.
High winds were expected to fan the flames overnight and officials said in a release Sunday evening, “there is a high probability the wildfire will reach the B.C. and Alberta border tonight and enter Waterton Lakes National Park near Cameron Lake.”
More than 40 firefighters and six firefighting vehicles have been deployed to the area.
The fire was sparked 10 days ago after a lightning strike in the Flathead Valley just across the border in B.C.
An evacuation order was issued for Waterton Lakes National Park on Friday and an evacuation centre set up in Pincher Creek.
Evacuees can check in by phone at 403-904-0021 or by emailing mdinfo@mdpinchercreek.ab.ca.
Waterton has a year-round population of only 105, according to the 2016 census, but its rugged mountain peaks and emerald lakes draw hundreds if not thousands of visitors a day in the summer months.
A further update is expected Monday.