All roads leading in and out of Yellowstone National Park were reopened on October 29 following a mass closure of roadways that occurred earlier this week. A snowstorm that blew through the area on October 26 caused a staggering 30 vehicular incidents in a single day inside the park, as drivers struggled to navigate ice, blowing snow, and extreme weather.

Mishaps included cars sliding off the road, stalling, and becoming stranded, reported Wyoming media outlet Cowboy State Daily.

The outlet’s meteorologist, Don Day, explained that the park, which sits at roughly 8,000 feet, lies in a unique climatic zone. While weather events may be mild outside the park, within it, even seemingly minor storms can have a big impact.

“The whole park is on an elevated plateau,” said Day. “Even the ‘lower parts’ of the park, like Lake Yellowstone, are still at a high altitude. That elevated plateau makes Yellowstone a ‘high island’ that creates its own weather, in a sense.”

The debacle was the first major winter event in Yellowstone National Park of the 2025 fall season, which may explain the many incidents, according to Day. He called it a “wake-up call for a lot of people,” adding that, “we have to remember how to drive in this, maybe not go so fast, and assume that if a road might look wet, it might be ice. Little things like that make a big difference.”

The winter weather system that caused the storm was especially well-suited to make the park’s interior roads particularly dangerous.

“It had a lot of moisture,” said Day, “and the upper-level wind pattern was just right to focus in on the park, especially as you got up into the higher elevations.”

Most of the vehicular mishaps were caused by black ice, according to Day. Many of Yellowstone’s roads are heavily shaded by tree cover, and even on sunny days, it can be cold enough for black ice to form.

“By 3:00 P.M., that sun angle is already low enough that the pavement may have already cooled off. What was wet an hour ago is now black ice, and that low sun angle plays a huge role,” explained Day.

Julie Argyle, the postmaster at the Lake Village Post Office inside the national park, told Cowboy State Daily that the vehicle mishaps came at a bad time, due to staffing shortages in the park resulting from the federal government shutdown.

“Not even the rangers were at full staff,” said Argyle. “I don’t know how many people on the road crews are working.” She recalled that during a previous snowstorm on October 12, “it took them longer than normal to clear the roads because of the people who weren’t there.”

The road closures came just days before the park was scheduled to shutter its East, South, and West entrances for the winter season. Most of the closed roads have since reopened, but on October 31, park officials will again block them off until late Spring 2026. Only the North and Northeast entrances of the park will remain open through the winter.

For current road conditions, visit Yellowstone’s park roads webpage.