Glacier National Park road crews carefully maneuver large machinery just feet away from the cliff’s edge as they push plows closer to Haystack Creek on the Going-to-the-Sun Road.

It’s “white knuckle territory,” said James Foster, the park’s maintenance head, but any wrong move while plowing the scenic mountain road could be life threatening.

There are 40 avalanche zones along the road, said Brandy Burke, the park’s public affairs assistant, and crews work early in the morning to avoid the warmer temperatures of the afternoon. High above, avalanche technicians ski the area and monitor conditions to ensure that they can give plenty of warning of an impending avalanche.

Becoming a Sun Road plower is something that typically starts in-house. Working up from maintenance positions, newbies plowing the Sun Road learn only from the people who have done it before them.

Engineering Equipment Operator Herb Ferguson said he’s been in his position for 23 years. He said it can be harrowing to be in one of the bulldozers they call “pioneer Cats,” named both for the heavy equipment company and because they are the first to go out on the road.

“You’re under new snow nobody’s ever been through, so you can feel all the changes in the snow underneath the bulldozer. So, sometimes you’ll push out and you’ll sink. You go out with the bulldozer and you feel this drop … so that’s always a little bit scary, but it’s a normal part of operating the machine,” Ferguson said.

He said there is a lot to look forward to when plowing the road, including ample animal sightings, like wolverines and bighorn sheep.

“You’re up here before everybody else — it’s beautiful,” Ferguson said. “And it’s kind of fun, even though there are certain things that are scary in your life, like when you go on a ride at the fair, it’s also fun.”

The danger of the job occasionally crosses his mind, but he trusts that the crew is following safety protocols to the best of their abilities when it comes to avalanches and maneuvering the large equipment on the narrow road.

“You can also make a mistake, which you don’t really want to do in some places, you could potentially go off the edge,” Ferguson said. “So, we try to minimize that by using techniques that we have for many years and building on those to make things safer and more of a process instead of ‘let’s go plow snow today.’”

He and other officials mentioned a phenomenon where water run-off from the side of the mountain forms “caverns” underneath the snow where crews are driving heavy equipment. This occasionally results in machines falling into large holes, occasionally big enough to ensnare an entire bulldozer.

Ferguson said this has happened a few times. Though it’s not necessarily dangerous, it can definitely make your stomach drop.

Officials said after the road is plowed enough, they come back through and do snow pulls and sweeping to clear off any additional snow and ice.

The Sun Road opens to hikers and bikers through the west side entrance on May 5, where it will be open to Lake McDonald Lodge. Burke said that typically the road doesn’t open to Avalanche Creek until around Mother’s Day weekend. Construction is still ongoing in that area and officials are warning visitors to prepare for bumpy and uneven roads.

The east side of the Sun Road is currently open to Rising Sun and is available to hikers and bikers.

To view where construction crews are working and how far the road is open under the current conditions tab, visit nps.gov/glac.