The rolling mountain scenery and lack of an obvious crater can sometimes make it easy to forget that Yellowstone National Park sits inside an active volcano.
Park officials say that the ground under a section of Firehole Lake Drive got so hot that it turned the asphalt into a sticky goop, forcing them to close the popular road during the height of the summer tourist season.
The 3.3-mile road, which loops around several geothermal features about six miles north of Old Faithful, reopened earlier this week after crews repaired the damaged asphalt and used a mix of sand and lime to soak up the pooled oil.
But before everybody loses their collective shit and fills your Facebook feed with paranoid gibberish, it's important to note that this sort of thing isn't uncommon in Yellowstone. The same massive chamber of molten rock beneath the park that drives the famous geysers and hot springs can also cause earthquakes and soften up roads, and it's fairly routine for new thermal features to pop up in parking lots or under roads and boardwalks—creating steaming potholes that rangers mark off with cones.
Park officials also say that some unusually hot weather—at least by Yellowstone (average elevation around 8,000 feet) standards—in the mid-80's helped the volcano turn the road into an oily soup.
But officials did warn people not to go hiking in the area, as scalding hot water could be lurking beneath a thin crust of rock and soil.
Park geologists say that despite the softened road and a recent swarm of earthquakes in the area, there remains no evidence that the Yellowstone supervolcano—which last had a major eruption about 600,000 years ago—was in any imminent danger of erupting.
Image via National Park Service