With water from the dammed Lowe River having fully receded, and ice from a half mile of roadway that had been submerged in flood waters removed, crews worked around the clock over the weekend to clear snow from the Richardson Highway north of the community of Valdez after a series of avalanches swept through the area in late January. The avalanches have closed the road the past 10 days, and although the highway may reopen this week, the Alaska Department of Transportation and Public Facilities' job will not be over.

All the snow left behind may not melt this summer, DOT said on Sunday.

A six-mile stretch of the Richardson Highway remained closed, DOT spokesperson Jeremy Woodrow said Sunday. But department officials estimate the road could reopen later this week.

The avalanches that buried around 1,500 feet of roadway under 40 feet of snow were the largest to clog the Richardson Highway in recent history, Steve Potter, northern region maintenance manager with DOT, said from Valdez on Sunday. Complicating the cleanup efforts initially was water that poured onto the roadway after the Lowe River was dammed by avalanches, forming a massive lake in Keystone Canyon that submerged roughly 2,500 feet of roadway and halted cleanup operations for days.

"That kind of scenario has never happened on the road," Potter said. Crews have removed ice and debris left behind on roughly half a mile of roadway. Now, they are tackling the snow. DOT estimates that between 100,000 and 500,000 cubic yards of snow must be removed. "The pictures just don't do it justice," Potter said. "It's impressive."

The river alongside the roadway was buried in 100 feet of snow. Snow removal crews are working 12-hour shifts around the clock "terracing it down" from the top to bottom, Potter said. "We can't just leave a 100-foot vertical wall" of snow.

Crews have to be careful not to get too close to the edge of the snow mass. And because of the flood waters, DOT has to be careful when dumping the snow due to possible pockets of water left behind on the side of the roadway. Because the canyon is so narrow, crews have to haul the snow north.

The road appears to be undamaged, as it remained frozen through the event and not subject to the freeze-and-thaw cycle that damages roadways every spring in Alaska. The Richardson Highway "shouldn't have any road damage as far as blowouts, soft spots, or anything like that," Potter said.

But there will still be heaps of snow lining the road, which will be visible during drives to and from Valdez. "That's not going to go anywhere anytime soon," Potter said.

Given the amount of snow and its location in shaded Keystone Canyon, there's a chance it may not fully melt over the summer. "There's that much snow," Potter said.

DOT will continue to monitor the snow. As spring breakup begins to shift the ice and snow, there's the potential snow could cave in and dam the river again. "It could get water on the road again, worst-case scenario," Potter said. DOT is clearing ditches and leaving the old highway tunnel across the road open, in case damming does occur come spring, so the water has somewhere to flow.

Contact Laurel Andrews at laurel(at)alaskadispatch.com. Follow her on Twitter @Laurel_Andrews