The tallest active geyser in the world may be erupting for the first time since 2014, according to the National Park Service.

Yellowstone National Park employees reported seeing the Steamboat Geyser erupt on Thursday evening, the park service announced Friday. Park geologists then compared the accounts to thermal sensors in the area and determined it “could be a series of minor eruptions.”

The geyser can shoot water higher than 300 feet during major eruptions, according to the Park Service. A geyser in New Zealand has sent water higher, but not in more than 100 years.