Across Montana, the route of Lewis and Clark's 1804-1806 expedition formed part of a broad venture to investigate the people and resources of the newly acquired Louisiana Purchase and to seek a navigable passage across the Rocky Mountains to the Pacific. Like earlier French and Spanish voyages across North America, the Corps of Discovery returned with information that changed life in this land. In the 19th century, as Indian nations recovered from five waves of smallpox and pushed west while Europeans raced to conquer more territory, Lewis and Clark came to the Northern Plains not simply to explore, trade, or trap, but for military, scientific, and economic development reasons, helping define agendas and relationships between cultures and between people and the land that continued to shape the West. The Corps of Discovery included Indians, French, Euro-Americans, men of mixed European and Indian descent, one black person, a woman, and a baby, and Indian people of many nations fed, guided, and helped the expedition with few violent altercations. In what is now Montana, the expedition explored 1,900 miles of wilderness, catalogued 63 species of plants and animals new to science, and charted significant geographic features, including Pompeys Pillar, the Great Falls Portage, the Three Forks of the Missouri, Lemhi Pass, Lolo Pass, Traveller's Rest, and the Upper Missouri Breaks. Montana's landscape still preserves places where the land, wildlife, and native plants resemble what the Corps recorded in their journals, alongside evidence of the cultural cooperation, conflicts, and collisions in values that have defined the region for two centuries.