Parks Canada staff say aggressive fire behaviour prompted the decision to have thousands of people flee the Jasper area late Monday night.
Up to 25,000 residents and visitors were evacuated from Jasper since the order was made on Monday, as two fires raged to the south and north, reaching within 12 kilometres of the townsite.
When asked how the fire was able to come so close to the townsite before the alert was sent, incident commander Katie Ellsworth recounted a rapidly evolving situation leading up to the evacuation order.
"The situation unfolded very, very quickly," Ellsworth said, noting it was only a two-hour time frame from the start of the fires to when they were estimated to be of significant size.
Thousands of wildfire evacuees forced from Jasper National Park into British Columbia along smoke-choked mountain roads Monday were directed Tuesday to make a wide U-turn and head home if they needed a place to stay, according to reports by The Canadian Press.
Alberta fire officials said B.C. has its hands full with its own wildfires and evacuations. "They had no capacity to house Albertans," Alberta Public Safety Minister Mike Ellis told The Canadian Press reporters.
Ellis told evacuees to take massive detours, either through Prince George, B.C., proceeding north and east to Grande Prairie, or south to Kamloops before going east to Calgary. The result was a long, slow-moving line of cars and trucks heading west through the mountains to B.C. in darkness, swirling smoke, soot and ash.
Many evacuees sought refuge for the night in Valemount, B.C., a town of 1,000 people about 120 kilometres west of Jasper.
Some evacuees spent the night on the floor of the local arena. Others bunked down at the legion. A local church was serving a pancake breakfast while drinks, snacks, information and respite were on offer at Valemount's community hall and visitors' centre.
Parks Canada states in their latest update there were no reports of injuries or serious situations.