Lewis and Clark identified 122 animal species new to science.

The expedition documented 240 plant species, 178 new to western science

Lewis and Clark’s botanical records introduced species to Americans like bitterroot, ponderosa pine, and Oregon grape—plants unknown to western science at the time. See a selection of these species in this image gallery.

The Corps of Discovery braved wildlife, weather, and near-starvation

Along their 8,000-mile trek through territory populated by tribes suspicious of their intentions, Lewis and Clark’s party faced many dangers—including grizzly bear attacks, freezing winters, treacherous river crossings, and periods of near-starvation. Watch a 30-minute elaboration of their heroic efforts here.

Discover the 'American Serengeti' Lewis and Clark first recorded

This podcast traces the 19th-century exploration of the Great Plains' biodiversity—beginning with Lewis and Clark's wildlife cataloging and continuing through a century of documenting the Natural West's remarkable species and landscapes.

Explore Lewis and Clark's 8,000-mile journey in Google Earth.

Lewis and Clark’s journey became a blueprint for future exploration

Combining science, diplomacy, and logistics, the Corps of Discovery created a model for later expeditions—from charting the Arctic to NASA’s space missions.

Lewis and Clark encountered more than 70 Native tribes during their journey

The Corps of Discovery’s diplomacy ranged from peaceful trade and vital aid from tribes like the Shoshone and Nez Perce to tense standoffs, most notably with the Teton Sioux, who nearly brought the expedition to a halt.

The Lewis and Clark Expedition unexpectedly ran into Sacagawea's long-lost family in the Rocky Mountains.

The expedition produced the first detailed climate records of the West

Lewis and Clark logged daily temperature, weather, and seasonal patterns throughout their journey, creating the earliest systematic meteorological record for the western territories of the United States. Their observations helped overturn longstanding views that weather west of the Appalachians was similar to the East Coast.

The Lewis and Clark expedition lasted over two years

The Corps of Discovery departed St. Louis in May 1804 and returned in September 1806, covering more than 8,000 miles by boat, horseback, and on foot. See a timeline of the journey’s key events.

The Lewis and Clark Expedition brought along an estimated 120 gallons of whiskey and still ran out of alcohol halfway through the journey.

Clark’s maps provided the first detailed record of the American West

Covering over 8,000 miles, William Clark’s maps charted rivers, mountains, and tribal territories with remarkable accuracy. Equipped with sextants, compasses, telescopes, and more, Clark became an expert at surveying—requiring extensive celestial and topographical observations each day.

The Lewis and Clark expedition purchased more than 260 separate items to supply their journey.

Jefferson’s Lewis and Clark expedition joined the centuries-long hunt for Northwest Passage

For centuries, leaders pursued a direct seafaring trade route from Europe to Asia. Jefferson joined this quest by sending Lewis and Clark west, though they confirmed no such practical interior route existed across the continent.

Native voices share their histories along the Lewis and Clark National Historic Trail

Tribal historians recount their peoples' histories and perspectives on the Lewis and Clark expedition, offering an Indigenous narrative of the lands, encounters, and legacies that shaped the journey.

Lewis brought his loyal Newfoundland dog on the expedition

Meriwether Lewis was accompanied by his dog, Seaman, a Newfoundland who traveled the entire journey—helping hunt, guarding camp, and even rescuing supplies from a river.

William Clark negotiated one-tenth of all ratified treaties between Native Americans and the US.

Jefferson sent Lewis and Clark to map, trade, and secure the West

Beyond seeking a water route to the Pacific, Jefferson tasked the Corps of Discovery with mapping the new Louisiana Territory, cataloging its resources, and establishing trade with Native nations.

Meriwether Lewis grew up in the same neighborhood as Jefferson

Hailing from Jefferson’s Albemarle County neighborhood in Virginia, Lewis was a trusted aide and former Army officer. After leading the Corps of Discovery, he became Louisiana Territory governor in 1806, dying three years later under mysterious circumstances.

Charles Darwin studied goose bumps by scaring zoo animals in London with a stuffed snake

Read the famous naturalist’s work from the late 1800s, detailing how he sought to draw comparisons between how animals and humans respond to fear. As part of that work, he exposed monkeys and a peccary to a stuffed snake and noted the animals’ hair-raising fear response.

Jefferson omitted a plan to go beyond the Louisiana Territory in his funding request

In January of 1803, the president sought $2,500 to fund the expedition (though it likely cost closer to $50,000). The ostensible rationale for the journey was to explore the newly purchased territory, but Jefferson did not mention he wanted Lewis and Clark to go beyond the newly acquired territory for several reasons.

The expedition included Clark’s enslaved servant, York

York, Clark’s enslaved servant, played a full role in the expedition—hunting, scouting, and aiding diplomacy with Native nations who were fascinated by his appearance. Despite his contributions, York remained enslaved for some time after the journey, though its uncertain if he remained so for the rest of his life. Explore every member of the Corps of Discovery here.

The first women to run the Colorado River discovered four plant species

Over 45 days and 660 miles, Elzada Clover and Lois Jotter identified more than 50 species in what was the first botanical survey of the region. Expected to help navigate boats and cook for the crew during the day, their work was confined to before dawn and after dusk.

Yellowstone was the world's first national park

Before it was designated as such, it was home to 27 Indigenous tribes, including the Blackfeet, Crow, and Nez Perce. European trappers and traders traveling west were entranced by the area’s stunning beauty and natural resources, fueling a push for the government to preserve the land for future generations.

A free archive of firsthand historical documents from explorers of America

Maintained by the Wisconsin Historical Society, the American Journeys collection contains more than 18,000 pages of primary source documents—journals, letters, maps, and accounts written between roughly 1000 CE and the early 1800s. These include eyewitness records of the Norse arrival in North America, Spanish conquistador expeditions, and the Lewis and Clark journey. Browse this list of highlights where pages from the original texts are specified (clicking a link opens a PDF).

Sacagawea's son, Jean Baptiste, who was born during the Lewis and Clark expedition, traveled to Europe as a duke's companion before returning to the American West.

River dolphins manhandle an unlucky anaconda

The natural world around us is endlessly inspiring, and fascinating, and often very odd too: like when researchers snapped a photo of Bolivian river dolphins swimming around with a Beni anaconda snake in their mouths, for example.

Review an historical exploration of Charles Darwin's expeditions

Darwin spent more than half of the Beagle expedition in Patagonia, discovering large mammal fossils, including extinct sloths. He journaled about the Argentine genocide of Indigenous peoples in the regions while making findings that would contribute to his theory of evolution.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

The Corps traded gifts with many native tribes as a sign of goodwill

They offered peace medals, beads, cloth, and mirrors, while receiving food, horses, furs, and guidance that helped them navigate and survive the western wilderness. This image collection showcases items the expedition collected.

Ten magnificent photos of lions

A new book of essays and images reveals the history of the big cats, elaborating on how they’ve become a vulnerable species today (and efforts to preserve them).

The Bone Wars turned paleontology into a rivalry fraught with public scandal

Othniel Charles Marsh and Edward Drinker Cope were friends-turned-enemies competing for the glory of discovering dinosaurs. It became so intense that when Cope died, he donated his body to science to prove he had a bigger brain than Marsh.

A French Army surgeon discovered that malaria is a parasitic disease in 1880—but scientists were initially skeptical

Charles Louis Alphonse Laveran won the Nobel Prize for his work "on the role played by protozoa" in causing diseases. His work included discovering and reporting the malaria-causing parasite in the blood of a patient suffering from malaria.

The Leopold Report was an early blueprint for ecosystem management

The 1963 report, officially known as Wildlife Management in the National Parks, recommended wildlife management and ecological preservation. In 2012, a follow-up report built upon the original paper to guide future park service policies based on scientific findings.

The Burmese pythons in the Florida Everglades and the spotted lanternfly—native to Asia and now found throughout the US—are among the invasive species accidentally introduced and spread by humans.

Explore over 46,000 pages of Charles Darwin's manuscripts

The American Museum of Natural History hosts almost 35,000 digitized folios related to evolution within the fields of botany and zoology from Darwin's Beagle voyage. High-resolution color images, geological findings, and annotated books from Darwin's personal library are also viewable.

A tense standoff with the Teton Sioux nearly ended the expedition

In 1804, the Teton Sioux seized a Corps of Discovery boat during a Missouri River meeting, sparking a dangerous standoff. The conflict eased only after careful diplomacy.

Sculptor and painter Charles M. Russell focused on the Old West

The Montana artist, known for his realistic portrayals of cowboys and Native American life, began to gain national attention after traveling to New York and establishing connections in the art world. Still, he spent most of his time in Great Falls, Montana, where he completed approximately 4,000 works.

Sacagawea’s skills and presence were vital to the expedition’s success

The group hired French-Canadian trader Toussaint Charbonneau and his wife Sacagawea to serve as translators. Sacagawea became invaluable to the Corps, as she could speak Shoshone and had a familiarity with the geography of the region. Acting as interpreter and cultural bridge, Sacagawea helped secure Shoshone horses, identified key landmarks, and signaled peaceful intent to other tribes.