Yellowstone Geology

The geology of Yellowstone and Grand Teton National Parks is unique and fascinating. From volcanic activity to rock formations, learn about the geological history of these spectacular natural wonders.

Our Yellowstone Geology tour will take you to Yellowstone Park and Grand Teton, not for wildlife and scenic tours alone, but in conjunction with geology tours if that is what excites you.  Geology tours begin from Teton Village or Jackson.  We will show and explain to you the Yellowstone geology and the Greater Yellowstone Ecosystem which includes Teton National Park.  For those who love the history of rock formations, volcanos, glaciers, hot springs, warm springs, fumaroles, and mud pots, you will enjoy the Geology of Yellowstone.  Even if you do not like geology, you will be able to appreciate why Yellowstone is what is it today.  

Grand Teton geology: nearly two hundred thousand years ago, glaciers from Yellowstone melted over a period of thousands of years.  Moreover, as it did, it brought rocks and soil to the Jackson Valley which was now a one-mile hole deep.  Moraine from the glacier filled the hole and made it flat the way it looks today.  Driving through the Tetons, you wouldn’t know a third historic event occurred perhaps half a million years ago. The earth's mantle could have cracked and released basalt volcanic magma.  The magma cut the Tetons vertically at least in one place and remains as a visible dyke today, according to a geologist. The basalt dyke is visible.  There is a second intrusion that is possibly a basalt dyke as well, perhaps there are more.  Grand Teton tours can be more fun with some understanding of Grand Teton Park geology.  

Credit-  Kendra Leah Fuller/Shannon Sullivan: Images of America, Grand Teton National Park.

Volcanic History of Yellowstone

How big is Yellowstone volcano? - Will Yellowstone erupt?  It could in the future.   Huckleberry Ridge eruption 2.1 million years ago and created the Island Park Caldera; Mesa Falls eruption 1.3 million years ago resulting in Henry's Fork Caldera and; Lava Creek Caldera eruption 640,000 years ago and it created the Yellowstone Caldera (Wikipedia).  

Blacktail Butte

Tour Inclusions

Grand Teton Sunrise Or Sunset Tours

Are $799 Only, For 1 To 4 People.

Tour inclusions

Blacktail Butte - Glacial Sediment Ridge

Blacktail Butte - Glacial Sediment Ridge.  North America has witnessed glaciation for 2.6 million years. National Park Service  The last two glaciations in Yellowstone are Bull Lake Glaciation 150,000 to 130,000 years ago. US Geological Survey   These were enormous thick ice that over time melted, and when it did, it moved sediment including soil, little rocks, and bigger ones.  Yellowstone Plateau sits at about 8,000 to 8,500 feet, while Jackson Hole is about 6,500 feet.  The two glaciers mentioned before eventually melted over periods of thousands of years.  And as they did, it brought with it moraine to the Jackson Hole Valley.  In the middle of Jackson Hole Valley sits Blacktail Butte.  "The butte is named after black-tailed  deer,  also known as mule deer." Wikipedia 

Blacktail Butte had its own share of sedimentary deposits over millions of years.  The butte is 7,688 feet (Wikipedia), and it is 6 miles as you drive from north to southwest on highway 89 toward the town of Jackson.  However, if you drive from Kelley to Jackson Wyoming, it is about 6 and a half miles.  The butte itself is about a mile, however, its sedimentary ridge makes up the remaining distances of 6 and 6 and a half miles.  Starting from the base of the mountain, the ridge is higher than a one-level house.  And the further it moves away, the shorter it becomes.

Whenever glacial melting occurred in Yellowstone, loose sediment got carried to the Jackson Hole Valley.  But upon reaching the Blacktail Butte, the moraine could not remain in front of the mountain, rather it was swept over the mountain where it settled behind the butte where it found refuge from the raging force of the water.  Further north away from the mountain, there are more ridges that reach the Snake River, and there are even more across the river as well.  Without the Blacktail Butte, there would be no ridge behind the mountain, instead, there would have been a lower ridge the same level as the one just north of the Butte.  Blacktail Butte is patronized by mountain climbers, and hikers.  That is also a hang-out for moose at times.  Check out our tours and book.  You will love it.

Eroding Glacial sediment on the east side of Black Tail Butte, Jackson Hole Valley
Glacial Sediment or Moraine Ridge, Blacktail Butte, Jackson Hole Valley

Earthquake tours - Yellowstone & Grand Teton

Earthquake tours.  Geology tours in Yellowstone and Grand Teton, include brief descriptions of earthquakes, glaciation, glacial melting, and geothermal and hydrothermal landmarks.  At the base of Rockchuck Peak, between Mount Moran and the Cathedral Group, there is a fault line.  Researchers have found that in the last 10,000 years, three earthquakes ranging between 6.6 to 7.2 magnitude on the Richter Scale have erupted NPS.  The fault line runs south, and it seems, it is the same as the one described by S. Wittke of  Harvard University.  He reported in 2016 that there is one of two fault lines south of the Blacktail Butte S. Wittke, Harvard University   According to USGS, The Largest earthquake "in the Rocky Mountains was a magnitude 7.3 earthquake at Hebgen Lake northwest of Yellowstone in 1959."  The earthquake caused fumarole to start in the Fountain Paint Pots as well as ground soil to spew out of the Sapphire Pool.  It is noteworthy that earthquakes may not result in volcanic movement in Yellowstone.  Again according to the USGS the concern is boiling water in geysers, "One variety of ground shaking called “tremor” is observed at Yellowstone's geothermal areas whenever water boils in a geyser."

Geological Tours - Inside Yellowstone

Geological tours in Yellowstone include geysers, hot springs, fumaroles, and mud pots.


Before you get to Lamar Valley, you see erratics (boulders) strewn all over the landscape.  Thousands of years ago, the melted glacier moved it from its original place to where they are at the moment.