Park staff closed the road between the north entrance and Mammoth Hot Springs Campground in Wyoming at 2:30 p.m. Crews used heavy equipment to clear the debris and reopened the road at 5:45 p.m., according to a news release from the park.
Park spokesman Al Nash said he was unaware of any injuries caused by the landslides.
The closure came on a day in which the park experienced a "heavy thunderstorm" and saw power briefly disrupted because of a small fire north of Yellowstone, he said.
The landslides occurred on the main canyon road between the southern section of the Gardiner River Canyon and the Montana/Wyoming state line.
"It has pretty steep hills, where folks often see rocks roll down," Nash said. "Well, now, it's more than that."
The park's other entrances remained open.
Shortly after noon Tuesday, smoke from a fire outside the park tripped power lines, including those that serve Yellowstone and the Gardiner area. That left some buildings in the park, including in the Mammoth area, without power and others operating with emergency generators, NorthWestern Energy spokeswoman Claudia Rapkoch said.
Service was restored by 1:30 p.m., according to a news release from the park.
The fire was on national forest land and contained at about an acre, a spokeswoman for the Gallatin National Forest said.