Volunteers are asked to bring their own cross-country skies. A 4.0 magnitude earthquake rocked the Yellowstone region in Gallatin County last Thursday afternoon. No damage or injuries were reported, but the tremor was felt in a widespread area. The Yellowstone region lays claim to being the second most active region of earthquake activity in the United States, following California. On any given day, numerous small earthquakes, usually 2.5 or less, may occur within Yellowstone's boundaries.
Most visitors never feel the tremors, but the quakes do affect the plumbing system of the geysers.
For example, a series of earthquakes on the western side of Yellowstone this past summer has been credited by some with causing an increase in geyser activity in Upper Geyser Basin, the home of Old Faithful Geyser. True winter weather has finally settled into the Yellowstone region. Temperatures for this week may not get above freezing, with lows at night approaching zero degrees. Some snowfall is expected.