Kim Weir, a Parks Canada spokeswoman, says the 10-square-kilometre fire is burning away from the Jasper townsite and doesn't pose a threat to the community, nearby cottages or Jasper Park Lodge.
She says the fire is about 14 kilometres away from the town in the Maligne Valley and is about 15 kilometres away from Maligne Lake.
Three Parks Canada fire crews supported by five helicopters and heavy equipment are busy fighting the wildfire, which officials believe was probably caused by lightning.
The road into the valley and campgrounds in the immediate area are closed.
The popular Rocky Mountain national park remains open, but with a complete ban on campfires.Greg Fenton, superintendent of Jasper National Park, said the fire north of Medicine Lake was "still out of control" but the plan of attack was to keep it from moving further south toward Maligne Lake, one of the most photographed spots in all of Canada.
He said Parks Canada staff, RCMP and commercial operators in the valley were all assisting.
"Evacuation activities are going well," he said. "It will take some time because it's a busy operational season, and (there are) lots of visitors both on Maligne Lake and some of the wilderness trails — the Skyline, as an example."
Fenton said while it might seem a daunting task to evacuate visitors from the expansive region in the Rocky Mountains, he said for the most part they know where people are.
"We work with the Maligne Tours operator that does the tour boats down the river, and they have a good sense of numbers," he said. "And we have a reservation system for back-country camping, and so we have a means of knowing how many people are on the Skyline, as an example, and approximately where they are, and we know where vehicles are at both ends of the trail."
The evacuation order affected the entire valley, including Maligne Lake and its iconic Spirit Island, a tiny clutch of trees surrounded by a ring of majestic mountains, three glaciers and pristine blue water.
Incident commander Dave Smith said 52 people who had been hiking along the Skyline Trail were ferried out by two helicopters that made about 12 trips.
"People are usually pretty excited when they're involved in something like this," he said of their reaction to being evacuated. "They weren't expecting to get a helicopter ride and weren't expecting to see some of the spectacle that Mother Nature can provide."
He said the helicopters dropped them off at the bottom of the valley where they were met by a bus and taken into Jasper. Parks Canada staff then either helped them get to their vehicles or found them places to stay for the night.
Smith said there were also a number of people who got out before the road was closed, and some others who were escorted in a convoy through the smoky area.
A group of people at the Coronet Creek campground in the area have been told to stay put until Friday, when they will be escorted out. Smith said they were in no danger from the fire.
"At this point, we wouldn't want to have anybody on the ground," he said. "It's far too unsafe — there's nowhere to land a helicopter to let people out. We have to basically let this fire get through today and then we'll start putting our plans together. There won't be people on the ground in this fire for a while."
Because national parks are a federal jurisdiction, Parks Canada will take charge of the fire.
"When you have a big fire flap like we have this year, you always have to have some people in reserve."
The fire was about 15 kilometres south of the town of Jasper, but Smith said the community is "100 per cent safe."
Lightning is suspected as the cause of the fire.