Explorers of the Upper Missouri River Region

The Upper Missouri River region (present-day Montana, North Dakota, South Dakota, Nebraska) was explored by a succession of fur traders, government expeditions, and adventurers from 1804–1835.

Key Expeditions & Figures

1. Lewis & Clark Expedition (1804–1806) – First systematic exploration; wintered at Fort Mandan (ND); reached Great Falls (MT), Three Forks, Lemhi Pass
2. Zebulon Pike (1806–1807) – Explored upper Mississippi, attempted Missouri headwaters; captured by Spanish in Colorado
3. Manuel Lisa (1807–1811+) – St. Louis fur trader; built Fort Raymond (MT, 1807), first permanent post on Upper Missouri; founded Missouri Fur Company
4. John Evans (1790s, 1819–1820) – Welsh explorer; mapped for Spanish, later U.S.; sought "Welsh Indians" myth
5. Joshua Pilcher (1823–1825) – Missouri Fur Co. president; Upper Missouri trade, Fort Tecumseh
6. William Clark (1825) – As Superintendent of Indian Affairs; treaty negotiations, Atkinson-O'Fallon Expedition
7. Jedediah Smith (1823, 1827, 1828–1829) – Mountain man; first American to cross South Pass, reach California overland; explored Yellowstone, Bighorns
8. William Ashley (1822–1827) – Rocky Mountain Fur Co. founder; pioneered rendezvous system; explored Green, Sweetwater, Bighorn basins
9. David Jackson (1829) – Ashley partner; Jackson Hole namesake; explored Tetons, Yellowstone
10. Benjamin Bonneville (1832–1835) – Army captain on leave; led wagon train over South Pass; explored Green River, Snake River, California; mapped extensively

Phases of Exploration

• 1804–1812: Government scientific/diplomatic (Lewis & Clark, Pike)
• 1812–1820s: Fur trade dominance (Lisa, Pilcher, Ashley, Smith, Jackson)
• 1820s–1830s: Transition to government scientific/topographical (Bonneville, later Frémont)

Legacy

These explorations mapped the region, established trade relations with tribes (Mandan, Hidatsa, Arikara, Crow, Blackfeet, Shoshone), and paved the way for Oregon Trail migration, settlement, and eventual territorial organization.