Places Discovered & Named by Lewis & Clark: Great Falls, Shoshone Falls, Lemhi Pass & More

The Lewis and Clark Expedition (1804–1806) mapped and named dozens of features across the Louisiana Purchase and Oregon Country. Here are the most significant — many still bear their names.

🗺️ Key Discoveries & Namesakes

1. Great Falls of the Missouri (Montana)

• Series of 5 waterfalls over 16 miles — portage took 3 weeks
• Now: Ryan Dam, Rainbow Dam, Black Eagle Dam — hydroelectric

2. Maria's River → Marias River (Montana)

• Named for Maria Wood, infant daughter of expedition member
• Major Missouri tributary — strategic for later trade

3. Shoshone Falls (Idaho) — "Niagara of the West"

• 212 ft (65 m) — higher than Niagara
• On Snake River — named for Shoshone people who guided them

4. Lewis River (Idaho/Washington)

• Snake River tributary — named for Meriwether Lewis
• Not to be confused with Lewis River in WA (Columbia tributary)

5. Clark Fork River (Montana/Idaho)

• Major Columbia tributary — named for William Clark
• Drains Cabinet Mountains, flows through Missoula

6. Lemhi Pass (Montana/Idaho Border)

• 7,373 ft (2,247 m) — Continental Divide crossing
• Gateway from Missouri → Columbia watershed
• Sacagawea's homeland — Shoshone reunion

7. Lolo Pass (Idaho/Montana)

• 5,233 ft (1,595 m) — Nez Perce trail, later Mullan Road
• Used on return journey — brutal crossing

8. Great Plains Traverse

• First systematic documentation of shortgrass prairie ecology
• Noted bison herds, prairie dogs, grizzlies, Native nations

9. Columbia River Descent

• Followed 600+ miles to Pacific — mapped rapids, tribes, confluences
• Named Cape Disappointment (WA) — missed ship, not ocean

10. Fort Clatsop (Oregon)

• Winter 1805–06 — 50 people, 3 months, rain, elk, diplomacy
• Reconstructed — Lewis & Clark NHP

📝 Naming Legacy

• 178+ geographic features named by expedition
• Many honor members: York (Clark's enslaved man) — Yorks Islands, MT
• Indigenous names often replaced — now being restored (e.g., Nimíipuu for Nez Perce)

Lewis & Clark didn't "discover" inhabited land — but they imposed a American cartographic imagination that still shapes the map.