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Geologic Wonders of the National Parks

Crater Lake National Park Badlands NP Death Valley NP Mount Rainier NP Glacier NPCraters of the Moon NM&P Aniakchak NM&P
Our National Parks preserve some of the most outstanding and unique geology within our country and the world. These memorable sites are too big for any museum and too beautiful to miss.

The National Parks preserve spectacular icons of our nation's geologic heritage and contain some of the world's finest examples of geologic phenomena. From glaciers to barrier islands, from volcanoes to dinosaurs, the parks have it all including arches, canyons, caves, mountains and sand dunes.

"The best geologist is the one who has seen the most rocks." If you're interested in geology and scenic landscapes, there is no substitute to visiting and experiencing geologic sites in the field. Here, we present life lists of the essential and premier geologic sites in the National Parks. Come and explore the world's most magnificent rock collection—your National Parks.

We also hope that you will be inspired to seek out a personal geologic experience and Find Your Park in other places. A park can be many different things to many different people. We encourage you to add your own geologic sites to the lists provided here.


  • A Full Life
  • An Adventurous Life
  • An Extreme Life
  • Find Your Park

A Full Life—Must See Geologic Sites

This list includes several must see geologic sites in our National Parks. These sites highlight America's rich geologic heritage and diversity. We hope you add these parks to your life list and visit them in the near future to enjoy everything they have to offer!

Badlands National Park. NPS Photo by Cathy Bell.

Badlands National Park, South Dakota

Badlands contains some of the worlds most bizarre and "alien looking" landscapes; classic examples of badland topography. The poorly consolidated bedrock consisting of loose sediment and volcanic ash is quickly eroded by infrequent rainstorms. Resulting mud mounds, spires, and ridges resemble miniature mountain ranges.
[Park Homepage] [Geology Fieldnotes]


Carlsbad Caverns National Park. NPS Photo by Peter Jones.


Carlsbad Caverns National Park, New Mexico

The Park contains more than 100 known caves, including the nation's deepest limestone cave at 1,604 feet and third longest. Carlsbad Cavern, with one of the world's largest underground chambers, displays an amazing array of cave and karst features. Rising sulphur-rich fluids mixed with fresh ground water to form sulphuric acid, which is responsible for the formation of this cave system.
[Park Homepage] [Geology Fieldnotes]

Death Valley National Park. NPS Photo.


Death Valley National Park, California and Nevada

Death Valley is world-famous for the incredible size, shape, and exposure of alluvial fans. One of the most stunning and archetypal is the Copper Canyon Fan, spreading out from the Black Mountains. The Black Mountain front is defined by a prominent fault scarp and the abrupt topographic transition from the mountains to the flat valley bottom creates ideal conditions for the formation of alluvial fans. In the deep channels cut into alluvial fans, the succession of fan deposits is easily observable; the darkest, most deeply desert varnished rocks are the oldest.
[Park Homepage] [Geology Fieldnotes]

Death Valley National Park. Photo courtesy of Ken Redeker.


Death Valley National Park, California and Nevada

Contains some of the best examples of playas and salt pans in North America. Playas, like "the racetrack" are shallow, transient lakes that form in closed basins and quickly evaporate whereas salt pans, like the ones at Badwater, are un-drained natural depressions where salt is deposited upon evaporation.
[Park Homepage] [Geology Fieldnotes]


Dinosaur National Monument. NPS Photo by David Tarailo.


Dinosaur National Monument, Utah and Colorado

Dinosaur National Monument is the archetypal dinosaur quarry and protects and displays classic fossil dinosaur bones including Allosaurus, Stegosaurus, Apatosaurus, and Archaeopteryx. The Quarry Wall in the visitor center houses over 1500 in situ bones, held in a river deposit within the world renowned Morrison Formation.
[Park Homepage] [Geology Fieldnotes]



Glacier National Park. NPS Photo by David Restivo.


Glacier National Park, Montana

The Lewis Overthrust is one of the world's largest and most famous thrust faults. A slice of Precambrian sedimentary rocks, over two kilometers thick and hundreds of kilometers wide, was thrust 80 kilometers eastward over softer Cretaceous rocks. Recent glaciations have exposed both layers and internal structures. In the eastern side of Glacier National Park, Chief Mountain provides a world class example of a klippe (an erosional remnant of a thrust sheet).
[Park Homepage] [Geology Fieldnotes]


Grand Canyon National Park. NPS Photo by Michael Quinn.


Grand Canyon National Park, Arizona

Hailed as one of the Seven Wonders of the World, the Grand Canyon exhibits the largest section of geologic time on earth. Hiking to the bottom, one passes through a third of the planet's age. The Park also contains excellent exposure of the world renowned Great Unconformity, an impressive angular unconformity, occupying 1.2 billion years in the rock record. The gap in the rock record straddles the Precambrian - Cambrian boundary and is found many places around the globe.
[Park Homepage] [Geology Fieldnotes]


Grand Teton National Park. NPS Photo.

Grand Teton National Park, Wyoming

The Teton Fault is one of the most notable normal faults in North America. The east-dipping tensional fault shows over 10 kilometers of structural relief, with a calculated uplift rate of over one kilometer per million years. The Teton Mountains rise steeply out of the eastern plain, highlighting the effect of the fault.
[Park Homepage] [Geology Fieldnotes]


Hawaii Volcanoes National Park. NPS photo by Dale Pate.


Hawaii Volcanoes National Park, Hawaii

Hawaii Volcanoes National Park contains the world's most massive mountain, Mauna Loa at 13,677 feet. Mauna Loa rises over 30,000 feet, when measured from its base on the seafloor, more than a thousand feet higher than Mount Everest. The park also contains Kilauea, the world's most active volcano. In contrast to explosive continental volcanoes, the more fluid and less gaseous eruptions of Kilauea and Mauna Loa produce awe inspiring, fiery fountains and rivers of molten lava that visitors can observe from a safe distance. Kilauea produces enough volcanic material every day to cover a football field to the height of the Washington Monument and has been erupting continuously since 1983.
[Park Homepage] [Geology Fieldnotes]

Mammoth Cave National Park. NPS Photo.


Mammoth Cave National Park, Kentucky

Mammoth is the longest recorded cave system in the world with over 400 mapped miles. Mammoth preserves part of an archetypal karst landscape in South-Central Kentucky with sinkholes, vertical shafts, windows, and springs amongst other features.
[Park Homepage] [Geology Fieldnotes]


Mount Rainier National Park. NPS Photo.


Mount Rainier National Park, Washington

Has the largest collection of glaciers on one peak in the contiguous U.S. The mountain has 25 named glaciers and 50 smaller, unnamed glaciers and ice fields. In the Lower 48, Mount Rainier National Park has the thickest and most voluminous glacier, Carbon Glacier, and the glacier with the greatest surface area Emmons Glacier. It is one of the most accessible places to view glaciers up close.
[Park Homepage] [Geology Fieldnotes]

Petrified Forest National Park. NPS Photo.


Petrified Forest National Park, Arizona

Features one of the world's largest and most colorful collections of petrified wood. In the Triassic, trees were washed away in storms and floods and buried in an extensive floodplain under silt, mud, and volcanic ash. Ground water carrying dissolved silica from the volcanic ash crystallized around or replaced cell walls. Replacement was often so exact that even the most delicate details of the logs were preserved.
[Park Homepage] [Geology Fieldnotes]



Yellowstone National Park. NPS Photo by Neal Herbert.


Yellowstone National Park, Wyoming, Montana, and Idaho

The Yellowstone Caldera is the largest in North America. The Yellowstone hotspot has actually produced three calderas in the Yellowstone region, the youngest of which is nearly 80 kilometers long and 50 kilometers wide. Up unitl 2 million years ago, there were caldera-forming eruptions roughly once every 600,000 years— future eruptions are expected.
[Park Homepage] [Geology Fieldnotes]

Yellowstone National Park. NPS Photo.


Yellowstone National Park, Wyoming, Montana, and Idaho

Contains over half of the 1,000 or so known geysers in the world, including "Steamboat," the world's tallest geyser. Yellowstone National Park sits inside an ancient volcanic caldera with magma, in some places only a few miles underground, powering the park's famous geysers, hot springs, fumaroles, and mud pots. Super-heated water, trapped in underground channels, sends bubbles of steam upwards which eventually "lifts" the water and causes the geyser to overflow. The overflowing geyser releases enough pressure to allow the trapped water to violently boil and the resulting steam shoots the water dramatically out of the ground.
[Park Homepage] [Geology Fieldnotes]

Yosemite National Park. Photo courtesy of Don Wood.


Yosemite National Park, California

Half-Dome is the classic and jaw-dropping example of an exfoliation dome. Located in perhaps the world's best example of a glacially carved canyon, Half-Dome's rounded appearance is due to sheet jointing (or exfoliation). The granitic pluton that formed the Sierra Nevada was slowly eroded, releasing pressure and causing the expansion of the underlying rock. Joints formed parallel to the earth's surface, which have since been exhumed and exposed. The sheer vertical face of Half-Dome, parallels regional joints and was carved out by glaciers.
[Park Homepage] [Geology Fieldnotes]

An Adventurous Life—Less Visited Sites

The Adventurous Life list covers less visited but equally extraordinary geologic sites in the National Parks. These far-flung destinations will take you off the beaten path to parks with spectacular examples of dune systems, columnar basalts, monoclines, crustal breaks, and more.

Aniakchak National Monument and Preserve. NPS Photo by Ike Fitz.


Aniakchak National Monument, Alaska

Aniakchak is located on the Alaska Peninsula, part of the Aleutian volcanic arc. The Aniakchak caldera is one of the youngest calderas in North America, erupting last in 1931 and is one of the finest examples of a dry caldera in the world. The Aleutian arc itself is one of the simplest and most visible subduction zones on Earth.
[Park Homepage] [Geology Fieldnotes]


Big Bend National Park. USGS Photo by Kenzie J. Turner.


Big Bend National Park, Texas

Contains a well preserved and clearly exposed section of rock spanning the K-T boundary, also referred to as the Cretaceous-Paleogene (K-Pg) boundary. Aproximately sixty-five million years ago the Cretaceous time period came to a close and the Tertiary time period began. This transition, known as the K-Pg boundary, is visible in the geologic record and marks one of the greatest mass extinctions of all time, and the end of the dinosaurs. Big Bend has the southernmost known exposure of terrestrial sedimentary rocks recording the K-Pg boundary in the United States. Big Bend is also relatively close to the Yucatan meteor impact crater believed to be responsible for the K-Pg mass extinction.
[Park Homepage] [Geology Fieldnotes]


Capitol Reef National Park. NPS Photo by Jack Wood.


Capitol Reef National Park, Utah

Contains a classic and well exposed monocline, the Waterpocket Fold. This nearly 100-mile long warp in the Earth's crust has lifted the rock layers on the west side more than 7,000 feet higher than the layers on the east. This giant fold has been deeply eroded exposing over 10,000 feet of continuous sedimentary strata. The Waterpocket Fold formed between 50 and 70 million years ago during the Laramide Orogeny.
[Park Homepage] [Geology Fieldnotes]


Denali National Park. USGS Photo.


Denali National Park, Alaska

The Denali Fault is the largest crustal break in North America. It stretches for 1,300 miles from the Yukon border down to the Aleutian peninsula. The Denali Fault is responsible for the largest North American earthquakes (magnitudes 8-9) in recent years. For example, the great Alaska earthquake of 1964 was magnnitude 9.2. The Denali fault marks the boundary where the Pacific Plate is being subducted by the North American Plate.
[Park Homepage] [Geology Fieldnotes]


Devils Postpile National Monumen. NPS Photo.


Devils Postpile National Monument, California

One of the world's finest examples of columnar basalt with continuous columns over 60 feet high. Uniform cooling conditions and homogeneity of the lava flows that filled the Middle Fork of the San Joaquin River to over 400 feet deep helped to form the almost perfectly hexagonal columns. Around 10,000 years ago, glaciers truncated and carved into the lava flow, exposing the interior. The Devil's Postpile is one of the prominent remnants of this glaciation.
[Park Homepage] [Geology Fieldnotes]

Fossil Butte National Monument. NPS photo.


Fossil Butte National Monument, Wyoming

Includes some of the most nearly perfectly preserved fossils of ancient plant and animal life in the world. Within the world renowned Green River Formation, Fossil Butte contains one of the world's best collection of fossilized freshwater fish, hundreds of insect species, uncounted plant species, and various other organisms such as bats, birds, turtles, and crocodiles. Fossil Butte originated as Fossil Lake, in which the constant precipitation of calcium carbonate helped to preserve the organisms which fell to the bottom of the lake.
[Park Homepage] [Geology Fieldnotes]

Great Sand Dunes National Park. NPS Photo.


Great Sand Dunes National Park and Preserve, Colorado

Houses the tallest sand dunes, over 750 feet, in North America and one of the most fragile and complex dune systems in the world. Sand and sediments deposited in the San Luis Valley were picked up by the fierce winds blowing towards the Northeast. The sands were deposited at the base at the Sangre de Cristo Mountains, which barred their passage, creating the enormous dunes in the high mountainous setting.
[Park Homepage] [Geology Filednotes]

Guadalupe Mountains National Park. NPS Photo.


Guadalupe Mountains National Park, Texas

Contains one of the Earth's finest examples of an ancient marine fossil reef. The 400 mile long Permian Capitan Reef, composed of the resistant Capitan Limestone, is well exposed in the Guadalupe Mountains. Guadalupe Mountains National Park is a must see for petroleum geologists interested in understanding reef systems.
[Park Homepage] [Geology Fieldnotes]


Olympic National Park. NPS Photo.


Olympic National Park, Washington

Surprisingly, one of the wettest parts of the country also contains one of the most dramatic rain shadows in the United States. Moisture is released from the air as it passes over the Olympic Mountains. Mount Olympus receives around 200 inches of precipitation a year, while the small town of Sequim on the northeastern corner of the Olympic peninsula receives less than twenty.
[Park Homepage] [Geology Fieldnotes]


Padre Island National Seashore. NPS Photo.


Padre Island National Seashore, Texas

North Padre Island is the longest undeveloped barrier island in the world. The National Seashore is 70 miles long with 65.5 miles of Gulf beach. The constant interplay between the wind, ocean, rivers, tides, and storms make barrier islands one of the most dynamic earth systems. The Park hosts a variety of pristine beach, dune, and tidal flat environments.
[Park Homepage] [Geology Fieldnotes]


Virgin Islands National Park. NPS Photo.


Virgin Islands National Park, Virgin Islands

The small island of St. John contains beautiful examples of coral reefs, white coral sand, and coral rubble beaches. There are excellent examples for each coral reef zone including striking reef flats and algal ridges.
[Park Homepage] [Geology Fieldnotes]

Voyageurs National Park. NPS Photo.


Voyageurs National Park, Minnesota

Voyageurs National Park, and Grand Teton National Park, Wyoming contain some of the oldest rocks in North America. Voyageurs, located in the southern portion of the Canadian Shield, displays rocks 2.6 - 2.85 billion years old. The oldest rocks in Grand Teton National Park are close to 2.7 billion years old and appear as complexly deformed metamorphic gneiss on Mt. Owen. The oldest rocks in America are located about 200 miles southwest of Voyagers and are up to 3.6 billion years old.
[Park Homepage] [Geology Fieldnotes]

White Sands National Monument. NPS Photo.


White Sands National Monument, New Mexico

Great wave-like gypsum sand dunes engulf over 275 square miles of desert and have created the world's largest gypsum dune field. Rain and snow melt flows from the surrounding mountains into the closed Tularosa Basin. Water pools in various playas and evaporates slowly causing gypsum to be deposited in a crystalline form called selenite. The forces of nature (freezing and thawing, wetting and drying) eventually break down the crystals into sand-size particles light enough to be moved by the wind and deposited in the White Sands dune field.
[Park Homepage] [Geology Fieldnotes]

White Sands National Monument. Photo courtesy of Ken Redeker.


White Sands National Monument, New Mexico

Contains one of the few examples of yardangs in the United States. Yardangs are streamlined, wind-eroded ridges found in arid regions. The White Sands' yardangs are well developed and impressive in size. The elongate yardangs form in the lightly cemented gypsum sand and are eroded by the prevailing southwest to northeast winds.
[Park Homepage] [Geology Fieldnotes]




An Extreme LifeSee the Highest, Deepest, and Widest

The following is a list of superlative geologic sites for those seeking to witness the highest, deepest, longest, and lowest of natural phenomena in our National Parks. These sites have inspired and enthralled generations of visitors.


Arches National Park. NPS Photo by Jacob B. Frank.

Arches National Park, Utah

Contains the greatest density of arches in the world. With over 2,000 catalogued arches, every stage of arch formation and deterioration is displayed. The world famous Delicate Arch, the remnant of a former fin, is one of the most striking, eye-catching, and well photographed arches, while the airy, Landscape Arch is one the widest in the world with a base of over 300 feet. Arches are fundamentally different from natural bridges in that bridges are formed by flowing water.
[Park Homepage] [Geology Fielnotes]


Crater Lake National Park. NPS Photo.


Crater Lake National Park, Oregon

Just under 2,000 feet, Crater Lake is the deepest lake in the United States and the second deepest in the Western Hemisphere. Mount Mazama, at one time rising over 12,000 feet in the Cascade Range, erupted around 8,000 years ago. The cataclysmic emptying of the magma chamber caused the mountain to collapse, forming a deep caldera that has subsequently filled with rain and snow melt creating Crater Lake. No streams flow in or out of the crater.
[Park Homepage] [Geology Fieldnotes]


Craters of the Moon National Monument and Preserve. NPS Photo.


Craters Of the Moon National Monument and Preserve, Idaho

Contains some of the best and most recent basaltic lava features in the conterminous U.S. spreading out over 600 square miles in the Snake River Plain. The lava fields, only 15,000–2,000 years old, occur along the Great Rift, displaying some of the best examples of open rift cracks in the world. There are extensive examples of pahoehoe, aa, block lava, tree molds, lava tubes, cinder cones, and many other volcanic features. Craters of the Moon represents the second, basaltic stage of the violent rhyolitic eruptions that helped to create Yellowstone National Park.
[Park Homepage] [Geology Fieldnotes]

Death Valley National Park. Photo courtesy Ken Redeker.


Death Valley National Park, California and Nevada

One of the hottest places on the surface of the Earth with summer temperatures averaging well over 100 degrees Fahrenheit. It encompasses the lowest surface elevation in the Western Hemisphere at 282 feet below the sea level, and it is the driest place in North America with an average rainfall of only 1.96 inches a year.
[Park Homepage] [Geology Fieldnotes]


Denali National Park. NPS Photo by Jacob Frank.


Denali National Park, Alaska

Mount Denali is the highest mountain peak in North America with an elevation of 20,320 feet above sea level. Measured by topographic prominence, Mount Denali is the third most prominent peak in the world after Mount Everest and Aconcagua. Numerous faults, including the Denali fault, demonstrate a long history of active plate tectonics in the area.
[Park Homepage] [Geology Fieldnotes]





Katmai National Park and Preserve. NPS Photo.


Katmai National Park and Preserve, Alaska

Largest volcanic eruption in the twentieth century. Mount Katmai, one of the volcanoes in Katmai National Park and Preserve, has proved upon investigation to have unusual size and character, and to be of importance in the study of volcanism. Its eruption in June 1912 was one of excessive violence, ranking in the first order of volcanic explosive eruptions and emitting several cubic miles of material during its first three days of activity.
[Park Homepage] [Geology Fieldnotes]


Keweenaw National Historical Park. NPS Photo.


Keweenaw National Historical Park, Michigan

The oldest and largest lava flow known on Earth is located on the Keweenaw Peninsula of Michigan. Volcanic activity at Keeweenaw produced the only place on Earth where large scale economically recoverable 97 percent pure native copper is found.
[Park Homepage] [Geology Fieldnotes]


Rainbow Bridge National Monument. NPS Photo.


Rainbow Bridge National Monument, Utah

The world's largest natural bridge is over 290 feet tall and 275 feet wide. At the site of Rainbow Bridge, water flowing through the Bridge Canyon drainage flowed in a tight curve around a thin fin of soft Navajo Sandstone that jutted into the canyon. Eventually this fin was breached and Bridge Creek changed course to flow through Rainbow Bridge. Under full conditions, Lake Powell obscures some of the height of Rainbow Bridge.
[Park Homepage] [Geology Fieldnotes]




Mammoth Cave National Park. NPS Photo by Dale Pate.


Mammoth Cave National Park, Kentucky

The longest known cave system in the world, with more than 400 miles of interconected passages explored. Mammoth Cave National Park preserves the worlds largest network of natural caves and underground passages, characteristic of karst landscapes. The park has high diversity of both terrestrial and aquatic cave-adapted creatures, including three endangered species—the Kentucky cave shrimp (Palaemonias ganteri), Indiana bat (Myotis sodalist) and Gray bat (Myotis grisescens).
[Park Homepage] [Geology Fieldnotes]




Yosemite National Park. NPS Photo by Greg Stock.


Yosemite National Park, California

Yosemite Falls is the tallest waterfall in the United States and the 5th tallest in the world at 2,425 feet. Every second 2,500 gallons of water pour over the lip of the hanging valley, which was created by glaciers during the most recent glacial period.
[Park Homepage] [Geology Fieldnotes]

Find out More

The Find Your Park campaign invites people everywhere to discover that a park can be more than a single place. It can be a trail, a heritage area, a seashore, a feeling of inspiration, or a sense of community that comes from volunteering.There is a national park in every state, and hundreds more local, state, and other public lands across the country. Using the links below you may find your park right in your own "backyard"! If your park is on Earth, it probably has a geologic story to tell.

Find Your Park
Find Your Park in America's National Parks!
There are many ways to find your park, and many places you can find it. Want to know where to start your journey? You can begin by searching Parks Near You.
Learn more...

America's State Parks
Find Your Park in America's State Parks!
America's State Parks work to enhance the American quality of life by capturing the collective strength and importance of the great park systems developed in the 50 states. Learn more...

American Trails

Find Your Park in America's Trails!
America's trails provide easily accessible places to get exercise and connect with nature in both urban and rural areas. Trails in the 50 states offer opportunities for Americans to explore local and regional geologic landscapes. Learn more...

Find Your Park in America's National Natural Landmarks!
The National Natural Landmarks Program recognizes and encourages the conservation of sites that contain the best examples of biological and geological features in both public and private ownership. There are currently 597 designated National Natural Landmark sites within 48 states, American Samoa, Guam, Puerto Rico, and the U.S. Virgin Islands. Approximately one-half of these landmarks are on public lands.
Learn more...

Americas Scenic Byways
Find Yout Park through America's Scenic Byways
America's Scenic Byways offer wonderful opportunities to travel to the parks and see a variety of geologic landforms. There are even Scenic Byways that connect parks using a geologic theme.
Learn more...

Related Links


Last Updated: October 08, 2015