Underground thermals at Yellowstone National Park melt tarmac road

The park's is on one of the world's largest supervolcanoes

Damage to a Yellowstone National Park road caused by thermal features in the park in Wyoming. (Yellowstone National Park/AP)

Geological activity at Yellowstone National Park has created a hotspot with temperatures high enough to melt tarmac roads.

Tourists trying to get to the park’s famous geysers are being diverted as officials try to fix the molten tarmac, which is not the only danger in the area.

The hotspot extends over land beyond the road, meaning hikers are at risk of stepping through what looks like solid ground into boiling water.

“There are plenty of other great places to see thermal features in the park,” said spokesman Al Nash.

“I wouldn't risk personal injury to see these during this temporary closure.”

Yellowstone’s roads and pathways are often damaged by its thermal features.

Steaming potholes in car parks and roads provide an added attraction for tourists.

But the damage to Firehole Lake Drive is unusually severe and could take several days to fix.

It is part of a three mile loop of road taking drivers past the Great Fountain Geyser, White Dome Geyser and Firehole Lake.

Weather in the park, mainly in the state of Wyoming, has been unusually hot in recent days, reaching 30C.

Yellowstone covers 2,219,789 acres and is home to one of the world’s largest “supervolcanoes”, the Yellowstone Caldera, which has sprung more than 10,000 thermal features and 300 geysers.

Additional reporting by AP