The South Klondike Highway was still closed today after three massive avalanches were brought down Wednesday afternoon using controlled explosives delivered by helicopter.

According to the territorial Department of Highways and Public Works, the highway, cordoned off between kilometres 80 and 106, should reopen later this afternoon.

"The snow on the road is quite excessive, and I've been told by work crews there that these are some of the biggest avalanches they've seen," Highways official Jen Magnuson told the Star this morning.

While not an unusual event in a region known for the highest avalanche activity in the territory, the highway was shut down at the noon hour Wednesday with barely an hour's notice.

"We need pinpoint accuracy when we drop explosives from a helicopter, so if there's overcast or anything that could negatively affect (this operation), then it's a no-go," Magnuson explained.

With dangerous amounts of snow piled high on the range near Tutshi Lake, clear skies and calm weather provided that window of opportunity crews were hoping for.

"It was a massive amount of snow that came down," said Magnuson.

Some 378 cm of snow had accumulated on the mountain above the highway compared to just 208 cm this time last year, she added.

In total, three avalanches came down; a pair just 200 metres apart at kilometres 81.4 and 81.6 and another at kilometre 84.2.

As of press time this afternoon, cleanup was continuing with four loaders - two working at either end of the snow slide.

Magnuson said the highway would open to single-lane traffic as soon as possible.

Skagway News publisher Jeff Brady, who travels on business to Whitehorse twice a month, was one person stranded in Skagway by the closure.

"Apparently it was closed off a good part of yesterday and customs told me this morning it's going to take another six to eight hours (to clear the highway) today," Brady said.

"This usually happens once or twice a year. At least I'm here in Skagway and not between the avalanches ... that wouldn't be very good."