Grand Canyon of the Yellowstone is arguably the most historically important painting associated with Thomas Moran. Created after his 1871 journey to Yellowstone, the monumental canvas transformed his field observations into a spectacular vision of the newly discovered landscape.

The National Gallery of Art explains that Moran's Yellowstone watercolors were used alongside William Henry Jackson's photographs as Congress considered legislation to protect the region. His enormous Grand Canyon of the Yellowstone was subsequently purchased by Congress and installed in the U.S. Capitol.

The painting therefore belongs to both art history and American environmental history. Moran did not merely depict Yellowstone; his imagery helped establish a visual argument for the extraordinary character of the region.

Chasm of the Colorado followed Moran's participation in John Wesley Powell's expedition down the Colorado River in 1873. It became the second of his monumental western landscapes to be purchased by Congress and displayed in the Capitol.

The National Gallery of Art identifies Grand Canyon of the Yellowstone, Chasm of the Colorado and Mountain of the Holy Cross as the three monumental western landscapes Moran repeatedly hoped to exhibit together.

These paintings are particularly important because they established a visual language for the American West in which enormous scale, geological drama, atmospheric colour and wilderness were combined into a single theatrical experience.

Mountain of the Holy Cross is one of Moran's best-known western paintings. The mountain's distinctive cross-shaped snow formation gave the landscape a powerful combination of geological wonder and religious symbolism.

Moran first encountered the subject through William Henry Jackson's photograph after the 1873 Colorado expedition. He subsequently travelled into the Rocky Mountains to make field studies of the mountain himself.

The resulting painting became Moran's major contribution to the 1876 Centennial Exposition in Philadelphia and helped establish his reputation as one of America's leading painters of the West.

The Teton Range demonstrates that Moran's fascination with western scenery continued long after his first Yellowstone journey. Painted in 1897, the work presents the dramatic mountain landscape south of Yellowstone in Moran's characteristic heightened colour.

The Metropolitan Museum of Art describes the Yellowstone region as one of Moran's signature subjects and notes that his dazzling watercolors contributed directly to the region's recognition as America's first national park.

The work also demonstrates Moran's characteristic use of prismatic colour to transform geological scenery into an emotionally charged landscape.

Tower at Tower Falls, Yellowstone is one of the most important surviving examples of Moran's Yellowstone watercolors. It records the landscape he encountered during the 1871 Hayden expedition and demonstrates his remarkable ability to translate geological formations into colour and atmosphere.

The National Gallery of Art identifies Moran as the first major artist to see and paint Yellowstone. His watercolors were particularly valuable because they provided vivid colour images of a landscape that most Americans had never seen.

The work was created in 1872 and is now in the National Gallery of Art collection.

Hot Springs of Gardiner's River, Yellowstone reveals Moran at his most attentive to Yellowstone's extraordinary geology. Mineral terraces, steam, water and rock formations become a richly coloured visual spectacle.

The National Gallery of Art notes that Moran's western watercolors are important both as historical documents and as exceptionally beautiful examples of nineteenth-century landscape painting.

The work is particularly useful for understanding why Moran's Yellowstone paintings were so influential: the colours and geological forms made the region appear unlike the familiar landscapes of the eastern United States.

The Grand Canyon: Head of the Old Hance Trail is an important later watercolor showing Moran's continuing engagement with Grand Canyon scenery.

The Metropolitan Museum of Art records the work as dating to around 1892 and identifies its combination of watercolor, pen and black ink, gouache and graphite underdrawing.

Unlike the monumental oil paintings, this work demonstrates Moran's ability to convey enormous geological space within a relatively compact sheet of paper.

The Juniata, Evening is particularly valuable because it reveals the side of Moran's career that existed before his western fame became dominant.

The National Gallery of Art notes that Moran produced important eastern landscapes before his first journey west in 1871 and that these works have only more recently received the attention they deserve.

The painting demonstrates that Moran was already a highly accomplished landscape artist before Yellowstone transformed his public reputation.

Minerva Terrace, Yellowstone belongs to the group of works through which Moran introduced the extraordinary geological formations of Yellowstone to a wider American audience.

The National Gallery of Art explains that Moran and photographer William Henry Jackson worked alongside the Hayden expedition in 1871, documenting the region's hot springs, geysers, waterfalls and other geological features.

These images became important visual evidence during the political discussions that preceded Yellowstone's establishment as the nation's first national park.

Moran's Yellowstone watercolors deserve to be considered as a major body of work rather than merely preparatory sketches.

He produced numerous studies of waterfalls, hot springs, canyons, mountains and unusual geological formations during and after the 1871 expedition. Their combination of observation and dramatic colour gave eastern audiences an unprecedented visual impression of Yellowstone.

The National Gallery of Art notes that Moran's watercolors played a decisive role in the creation of Yellowstone National Park. Congress saw them alongside Jackson's photographs as lawmakers considered protecting the region.