A mudslide near Pahaska Tepee closed down the East Entrance to Yellowstone Park on Sunday morning.
Early morning thunderstorms led to heavy rain and the slide covered both lanes of the North Fork Highway.
Chris Jones, a meteorologist with the National Weather Service in Riverton, said about a half inch of rain fell in under 30 minutes.
The same amount of rain in an urban area would cause street flooding, where water would rise above the sidewalks, Jones said.
“A half inch in an urban area can cause problems,” he said.
The slide caused the east gate to close 6:30-10 a.m. Sunday, Yellowstone spokesman Al Nash said.
A truck ended up stuck in the slide. It was traveling in the rain and was on top of the slide, said Jim Berry, maintenance foreman for the Wyoming Department of Transportation in Cody.
Berry said traffic began moving again at 9:30 a.m. and the two lanes were open by 12:30 p.m.
Jones said the area around the east gate, which has steep sides and sometimes low vegetation, has been known to have slides in the past.
(Nathan Meacham can be reached at email@example.com.)