Yellowstone National Park only just recently re-opened its gates to tourists, but things got a little busier than anticipated early Friday, with the first of 11 earthquakes in 24 hours. That first temblor was a 3.1, while the rest registered between 1.6 and 2.5, reports the Idaho Statesman. "Yellowstone is one of the most seismically active areas in the United States,” per the park's website, which cites between 700 and 3,000 earthquakes annually, though "most are not felt.” The area has seen 34 earthquakes in the last 30 days. (More Yellowstone National Park stories.)