At the same time, the world-famous Steamboat Geyser erupted twice last month, on January 9 and January 23 respectively.
The current volcano alert level for Yellowstone is NORMAL and there are no indications of an eruption brewing deep underground.
According to the USGS, there is also no evidence to support the idea Yellowstone is overdue another blast, based on past eruptions alone.
Yellowstone’s last major eruptions took place some 640,000 years, 1.3 million and 2.1 million years ago.
The USGS said: “First of all, one cannot present recurrence intervals based on only two values. It would be statistically meaningless.