After weeks of intense work, Yellowstone National Park’s massive snow removal operation has reached Sylvan Lake high in the mountains of northwest Wyoming.
That puts the crews less than 10 miles away from the park’s East Entrance.
There might be a record-breaking low snowpack around Wyoming, but there are still several feet of snow that needs to be cleared from Yellowstone’s roads before the summer season officially begins in mid-May.
Snow removal operations usually begin in early March. From there, it’s a slow but steady push through the park’s interior as a convoy of heavy machinery gets everything ready for summer.
“They can usually do 6 miles a day, working four days a week,” Yellowstone author, employee, and winter keeper Jeff Henry told Cowboy State Daily in March 2025. “An old friend of mine, who started doing this kind of work in 1973, said it’s the hardest work in Wyoming.”
An Organized Operation
Yellowstone’s winter season stretches from Dec. 15 to March 15.
During those months, the snowpack is kept intact for the snowmobiles and snowcoaches that offer winter excursions into the park, usually doing a constant circuit from Mammoth Hot Springs or West Yellowstone, Montana, to the year-round amenities open at Old Faithful.
Before the park’s winter season officially ends, everything and everyone needed for the multi-week snow-clearing operation mobilizes at Mammoth. The coordinated effort of man and machine functions more like a military convoy than a bunch of snowplows.
“They usually have a bulldozer or two chained to a grader with a heavy-duty V-shaped plow leading the procession,” Henry said. “The snowplow provides the impetus, and the bulldozer pulls the plow. That breaks up the hard-packed snow on the road.”
From Mammoth, the slow-moving convoy of construction vehicles begins a relentless push south, following the interior roads and tearing through hundreds of miles of hard-packed, several-feet-thick snow and ice.
The icy rubble left by the bulldozers is cleared by a convoy of seven massive rotary snowplows capable of clearing 4,500 tons of snow rubble and sending it to the roadside, away from the pavement.
Anything that's too stubborn for the multi-ton machines can be broken up by chainsaw-wielding crew members.
The convoy continues with multiple bulldozers, graders, and other large vehicles equipped with plows and blowers, advancing and expanding on the progress started by the lead vehicles.
In 2025, Yellowstone’s construction convoy departed Mammoth on March 3. It reached the Norris Geyser Basin two days later, clearing 21.6 miles of snow-covered roads to reach the critical junction to open the Grand Loop Road.
From Norris, the convoy turns eastward to Canyon Village. That’s a shorter distance, 12.3 miles, but it can take around six days to complete.
Henry said the snow removal operation is logistically impressive. It’s planned to maximize everyone’s time and minimize their efforts.
“They’ll set up camp at places like Lake Village and Canyon Village once they reach them,” he said. “They’ll stay in the buildings with a mess hall and a cook and use them as a base for the next several weeks.
"That way, they only have to drive down on Monday and back on Thursday at the end of their work week.”
Working Their Way Up
Clearing the bulk of the interior roads is the easy part of Yellowstone’s snow removal. The convoy usually has the northern half of the Grand Loop Road from Mammoth Hot Springs to Fishing Bridge cleared for regular vehicles by the beginning of April.
That’s when the effort gets trickier. The convoy usually departs Fishing Bridge for a three-day push along the much higher, narrower road to reach the East Entrance in early April.
Once the convoy reaches the East Entrance, it will head back down and clear the road from Grant Village to the South Entrance. The final stretch of the Grand Loop Road, from the West Thumb Geyser Basin to Old Faithful, is cleared by the beginning of May.
Henry has spent nearly 50 years working as a winter keeper at Old Faithful. His job is to clear snow from the roofs of the buildings in the area to prevent them from sagging or collapsing under the weight of 10 to 12 feet of accumulated snow.
“Our philosophy is to start clearing the snow as soon as possible,” he said. “The first snow is usually soft and powdery and won't hold together, but as soon as it bonds, we try to get it off because it comes down fast, and soon all of your buildings are alarmingly loaded.”
Fortunately, all Henry has to do is get the snow off the roof. Everything he pushes off is cleared up by the snow removal convoy once it reaches him.
The final two phases of the operation are clearing the Dunraven and Beartooth passes. If everything goes according to plan, every road in the park will be cleared of that season’s snowpack by mid-May.
“Beartooth Highway is always the last thing they plow,” Henry said.
Winter’s Final Wake-Up Call
The Wyoming Department of Transportation has mostly finished its effort to clear U.S. Highway 14/16/20 to the East Entrance. They anticipate that it’ll be clear enough for them to remove the road barriers by April 13.
Regardless of when and how much progress they make, the East Entrance of Yellowstone won’t officially open until at least May 1. The park’s interior roads may still close due to snow after the park officially opens, but those are usually temporary.
For Henry, there’s nothing as serene as the isolation of winter in Yellowstone National Park. For him, the impressively organized and efficient snow removal convoy is a noisy reminder that winter is over.
“It’s incredibly noisy, incredibly (smelly), and shatters the winter isolation,” he said. “Henry David Thoreau was sitting out in a peaceful countryside when a train came through and ruined it all for him. The plowing operation is the ultimate example for me.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
