Connecting the environment of the ancient past with the natural and cultural history of yesterday and today.





A Living Stage of Our Past, Present, and Future

Marine Gardens north of Newport, Oregon tells a story of “Beauty and the Beast.”

The convergence of tectonic plates that forms the magnificent scenery is also

responsible for life-threatening earthquakes, tsunamis, and landslides.


by Robert J. Lillie, Allyson Mathis, and Roger Riolo

Published January-February, 2011 in Legacy,

National Association for Interpretation

Reprinted with permission of the authors (all photos courtesy Bob Lillie)


   Geology tells the story of our past, establishes the foundations of our present, and reflects how we sustain our future. It provides the stage, furnishes the plot, and determines the cast for the episodic drama of natural and cultural history. This theme can help guide a holistic approach to interpretation by creating opportunities for a variety of audiences to find deeper meanings in the places they know and cherish.

   The National Science Foundation recently published a list of Earth Science Literacy principles ( that the public should know about our planet’s landforms, processes, and connections to society. One of the “Big Ideas” is, “Earth is a complex system of interlocking rock, water, air, and life.” This “Earth Systems” perspective is interpretive, as it highlights connections. Matter and energy move from one system, or sphere, to others and large changes in one sphere are likely to affect the other spheres. Ecosystem dynamics, climate change, landscape development, and human population movements can be understood by emphasizing how we affect and are affected by Earth’s spheres. We’re part of life (biosphere). We breathe and pollute air (atmosphere). We drink and contaminate water (hydrosphere) and live on a dynamic layer of rock (lithosphere) that shakes, breaks, erupts, and erodes to form inspiring landscapes.

   Geology adds meaning and understanding to biology, ecology, and human history. It provides the foundation for formulating whole stories. An Earth systems-based theme such as “Geology sets the stage for life, ecology, and human history” can foster new perspectives to audiences at many parks, forests, historic sites, and heritage areas. Yet it is only one of many concepts that can be used to interpret a site’s geology and its deeper meanings to the visiting public.

Methods and Strategies for Incorporating Earth Features and Processes into Interpretive Programs

   In many ways, interpreting geology is similar to interpreting any other topic: know the resource, understand the audience, make it relevant by employing interpretive techniques, and present a compelling story. Yet, interpreting geology offers some unique and challenging opportunities, as it may seem foreign compared to other natural or cultural history topics.

   Geology can be put into social and cultural contexts by using real-world applications. Landscapes can be tied to universal concepts such as change, power, and time that are likely to resonate with most any audience. Rocks can be viewed as landforms and building blocks for landscapes. Rock layers represent an enduring history book. Every rock tells a story. Interpreters can help visitors find deeper connections to the meanings of their site by using methods and strategies that present geology as an integral part of the site’s natural and cultural history.

   Interpret Geology as Part of a Larger Story: Geology is the study of landscape features and processes that make the Earth come alive; it is part of every story. Geology dictates climate

and environment and determines what life can exist in an area. It tells us how Earth formed and changed over vast expanses of time, and continues to be modified in ways that affect us all. Such stories create interest using high drama, intrigue, life, death, action, change, speculation, and provocation.

   Highlight Scenery: The visual impact of scenery can create a

connection between geology and the visitor, even if the connection is not initially appreciated. Scenery is a main reason why people visit many parks, monuments, forests, heritage areas, and other special places. Scenery at many interpretive sites is dominantly geologic. If a site has scenery, it has geology! Tell the landscape story by revealing how geologic processes are responsible for scenery. This improves understanding, enhances meaning, and builds a more complete natural history for the site  and its surrounding region.

   Invoke Sense of Place: Fostering a sense of place, or an appreciation of the meanings and attachments that people assign to locales, is at the heart of interpreting geology. It ties cultural and spiritual values to geological features and processes. An awe-inspiring and continuously active landscape captivates with its beauty, power,

energy—and sometimes danger!

Interpretation should address the whole person. In order to accomplish this we first must address the whole story, including the sense of place represented by geological processes and their bearing on landscape development.





Sunset Crater Volcano National Monument in northern Arizona

reveals how geological processes impact society, ecology, and

scenery. Volcanic eruptions 1,000 years ago disrupted lives,

changed ecosystems, and left behind a picturesque cinder cone.

   Relate, Relate, Relate: The use of analogies, similes, and metaphors can draw on visitors’ personal experiences to help them understand and connect to the deeper meanings of geological features and processes. We can compare geological processes and rates to known ones. For example, tectonic plates move at about the rate your fingernails grow; cinder cone eruptions are “volcanic fire works”; lava flows like honey and can crust over like ice forming on a river in winter. Sedimentary layers are stacked like pancakes—the oldest (first made) are at the bottom and the youngest are on top. People living near faults have natural seismometers hanging from their walls—photos that move during earthquakes.

   Interpret Deep Time: Earth’s history spans 4.5 billion (4,500 million) years. Such “deep” geologic time can inspire a sense of awe and wonder, and is hard for many people to cognitively appreciate. Geologic time can be put into perspective by comparing the age of the Earth to a day, a year, a yardstick, or other measurement tools.

   Present Geology as Part of Human History: Geological features and processes often determine transportation corridors, influence the outcome of battles, dictate cultural activities, and guide humankind’s responses to natural disasters. For example, New York was destined to become a great city because of its outstanding harbor. Much of the history of the American West has been influenced by the region’s great mineral wealth and semi-arid to arid climate. San Francisco is attractive because of the beauty of its natural landscape—but the same geological forces that form the landscape also cause devastating earthquakes.

   Demystify Geology: Geology reveals hidden stories. Interpreters should strive to explain the scientific understanding behind statements of geologic facts and theories. Incorporating answers to common visitor questions— such as explaining geologic dating techniques, identifying the sources of knowledge about Earth’s interior structure and composition, and techniques to interpret the climatological history of the planet—help visitors form meaningful connections to a site.

   Connect Geology to Life: Connections may be demonstrated by starting with living things and linking them to the landscape or starting with geology and linking it to living things. Rocks are habitat—home to plants, animals, and people. On a larger scale, Earth itself is home. Rocks provide material resources. They provide raw materials we use in our daily lives. The incredible biological diversity of the Grand Canyon, which contains the greatest number of species of vascular plant of any national park, is a result of geology. Ecosystems ranging from the Sonoran desert to boreal forest are found in the park from river to rim. Geology-ecology relationships can make geology more relevant. The 1964 Great Alaska Earthquake was a factor in the establishment of national wildlife refuges in the Willamette Valley of Oregon. Sudden movement of the Pacific tectonic plate during the earthquake raised parts of Alaska’s Copper River Delta, leaving much of the wetland nesting ground for the dusky Canada goose high and dry. Habitat for this species was expanded by developing William L. Finley, Ankeny, and Baskett Slough National Wildlife Refuges along their flyway in Oregon.

   Highlight How Geology Continues to Affect Our Lives: Geology is not something that happened long ago and is now finished. Many of the same processes that formed a site’s landscape and its rocks are still affecting the site today. For example, rivers carrying sediment eroded from the Appalachian Mountains deposit sand that forms the beautiful beaches of Cape Hatteras and other national seashores along the Atlantic coast. Landscapes such as the Grand Canyon are still being shaped by erosional processes and agents, such as the powerful Colorado River, the rush of flash floods and debris flows in side canyons, and the suddenness of massive rock falls. All of these processes continue today, maintaining the beauty of places we cherish. Interpretation can infuse the sense of wonder about ongoing geological processes and how human activities might upset their balance and adversely affect the landscape.

   Present Geology in Emotional and Poetic Terms: Interpreters can use emotion and poetry to help visitors appreciate geology in more human terms. Geology programs can include beauty, discovery, and excitement; visualizations of a dynamic Earth; and fun! A program might revolve around the concept of “Beauty and the Beast,” with a potential theme: “The same tectonic forces that threaten our lives with earthquakes, volcanic eruptions, and landslides also nourish our spirits by forming the magnificent mountains, valleys, and coastlines of the Pacific Northwest.”

The landscape of Yosemite National Park provides clues for a geological detective

story. The large mineral grains within the granite must have formed slowly as magma

cooled deep within the Earth. Miles of overlying rock— including ancient volcanoes

fed by the magma—were removed by erosion as the Sierra Nevada rose.

U-shaped valleys reveal that Ice-Age glaciers are a recent contributor to this process.

   In Reading the Rocks: The Autobiography of the Earth, Marcia Bjornerud wrote, “Unfortunately, stone has an undeserved reputation for being uncommunicative. The expressions stone deaf, stone cold, stony silence, and simply, stoned, reveal much about the relationship most people have to the rocks beneath their feet. But to a geologist, stones are richly illustrated texts, telling gothic tales of scorching heat, violent tempests, endurance, cataclysm, and reincarnation.”

Example of an Interpretive Program that Integrates Geology, Ecology, and Culture

   Hayden Valley—Life above a Hotspot: A crisp summer morning in Hayden Valley in Yellowstone National Park is a nice setting for a family hike. Adding a park ranger into the mix only improves upon the perfection of a perfect morning! The topic of the ranger program is geology. However, the family is surprised by so much conversation about grass-covered wetlands, lodge pole pines, bison, elk, and even the comings and goings of people.

   The ranger poses a question: What is it about Yellowstone that has resulted in such breathtaking scenery, fascinating ecology, and intriguing human history? At 8,000 feet above sea level, Hayden Valley’s climate is more like northern Canada than the continental USA. During the past ice age, a mini-ice sheet covered the entire Yellowstone Plateau. Trees along the edges of Hayden Valley outline an ancient glacial lake. Yellowstone has long attracted people as fertile ground for hunting, fishing, recreation, and obsidian tools. Only its lofty elevation prohibits year-round habitation.

   Another question: Why is the Yellowstone region so high? Yellowstone has a high elevation because it lies above the Yellowstone Hotspot, a region of Earth’s mantle that is so hot that it expands like a hot-air balloon and lifts the Yellowstone Plateau half a mile above the surrounding region. Expansion of the hot mantle also causes rock to melt. This process created the Yellowstone Supervolcano, a feature so vast and subtle that it was not recognized until satellites provided the needed perspective. The short growing season at high elevations and acidic soils from weathering of volcanic materials make Yellowstone a prime landscape for lodgepole pine trees. Particles of sediment deposited on the glacial lake bed are both large and small, so that water can’t easily seep through—standing water on the floor of Hayden Valley thus provides rich wetland habitat for abundant wildlife.

   And a most-intriguing question: Does anyone feel the urge to play golf? The game of golf was developed in Scotland, and most courses mimic Scotland’s glacial landscape. A trip to Yellowstone is like going to Scotland. The rise in elevation above the Yellowstone Hotspot is equivalent to traveling that far north. Hayden Valley’s golf-course appearance—long grassy fairways running through trees, with small ponds and pockets of sand—formed as Yellowstone’s ice sheet melted.

   The ranger concludes by explaining how geology sets the stage and creates the roles for all life, ecology, and history. If the stage were different, the play would be different and it would attract a different set of actors. Without high elevation and volcanic activity—products of the Yellowstone Hotspot—all aspects of Yellowstone’s life, ecology, and human history would be different.


Robert J. Lillie is a professor of geology and Certified Interpretive Trainer at Oregon State University. Reach him at

Allyson Mathis is the science and education outreach coordinator with Grand Canyon National Park’s Division of Science and Resource Management.Reach her at Allyson_Mathis@

Roger Riolo is a Certified Interpretive Trainer and owner of InterpTrain Interpretive Training & Consulting. Reach him at rlriolo@


Created February 1, 2011