The Ohio River: Where the Journey Begins

Starts: Pittsburgh, PA | Joins the Mississippi: Cairo, IL | Length: 981 miles
Ohio gets its name from the Ohio River, which traces its linguistic roots to the Seneca word ohi:yo’, meaning “good river.” This important waterway played a vital role in shaping the region’s identity and history.

On August 31, 1803, Meriwether Lewis departed Pittsburgh in a 55-foot keelboat, beginning the voyage that would change history.
👉 Fun Fact: The Ohio River forms where the Allegheny and Monongahela meet—known as “The Point” in downtown Pittsburgh.
 

The Missouri River: Artery of the West

Headwaters: Jefferson, Madison & Gallatin Rivers, MT
Mouth: St. Louis, MO | Length: 2,540 miles
The Missouri is the longest river in the U.S., and the lifeline of the Lewis and Clark Expedition.
In the formative years of the United States, the Missouri River served as a natural boundary between the established eastern settlements and the vast, largely unexplored lands to the west. This region, shaped by its waterways, became a key departure point for thousands of pioneers heading into frontier territory along routes such as the Santa Fe Trail, the Oregon Trail, and pathways that followed the Great Platte River.

📝 July 28, 1805 – Captain Lewis writes:

“We called the S.W. fork Jefferson's River in honor of Thomas Jefferson. The Middle fork we called Madison’s... and the S.E. fork Gallatin’s... all of them with great velocity and throw out large bodies of water.”
 

The Salmon River: The River of No Return

Length: 425 miles | Nickname: River of No Return

“The River of No Return,” the Salmon River begins in Idaho’s Sawtooth and Lemhi Valleys, fed by snowmelt from surrounding mountain ranges including the Sawtooth, Salmon River, Clearwater, and Bitterroot Mountains. Its upper reaches wind through the remote Frank Church–River of No Return Wilderness, while the lower stretch marks the southern edge of the Gospel-Hump Wilderness.

Carving through the second deepest canyon in North America—deeper even than the Grand Canyon in some places—the Salmon River flows for about 180 miles through a rugged landscape where the canyon exceeds a mile in depth. Near the town of Shoup, ancient rock formations known as gneiss have been uncovered, some dating back 1.5 billion years. Geologists believe the canyon itself began forming roughly 35 to 45 million years ago.
Explored: August 19–22, 1805

Clark and his team followed the river, but soon realized its steep gorges and violent rapids made travel impossible.
📝 Clark’s journal, August 23, 1805:

“My guide and maney other Indians tell me that the Mountains Close and is a perpendicular Clift on each side, and continues for a great distance and that the water runs with great violence from one rock to the other on each Side foaming & roreing thro rocks in every direction, So as to render the passage of any thing impossible”
👉 The River of No Return is infamous for its strong currents and rapids, making it difficult to navigate upstream. This river is a major component of the Frank Church-River of No Return Wilderness, the largest contiguous wilderness in the Lower 48.
 

The Clearwater & Lochsa Rivers

Route: Along U.S. Highway 12
These rivers run beneath the Lolo Trail, a National Historic Landmark that mirrors the Corps’ 1805–1806 route through Idaho and Montana.

Winding through the Clearwater National Forest for nearly 100 miles, the Middle Fork Clearwater and Lochsa rivers flow through lands long inhabited by the Nez Perce people. These two rivers were among the first in the nation to receive protection under the Wild and Scenic Rivers Act.

Paralleled by Highway 12—a route recognized as a National Scenic Byway—this corridor follows a dramatic canyon carved by water and time. Today, the river valley supports a thriving recreation scene while continuing to hold deep cultural importance for the Nez Perce Tribe.

👉 Known for dramatic switchbacks, rich tribal history, and alpine beauty, the Lolo Trail is a treasured stretch of the Lewis and Clark Trail.
 

The Snake River: Once Lewis’ River

Length: 1,040 miles | Joins the Columbia River
The Snake River—Idaho’s most well-known waterway—is a key tributary of the Columbia River. Originating in Yellowstone, it winds its way through southern Idaho’s Snake River Plain, then heads north and exits the state at Lewiston. There, at the meeting point of the Snake and Clearwater Rivers, you'll find the Port of Lewiston—the West Coast’s most inland seaport, located 465 river miles from the Pacific Ocean at Astoria, Oregon.
On October 10, 1805, the expedition reached this powerful river—home to salmon-rich waters and Nez Perce homeland.

📝 Clark wrote: “Lewis’ River is about 250 yards wide... the Koos Koos ke [Clearwater] River about 150 yards... below the forks about 300 yards wide.”
👉 Note: "Lewis’ River" was the name Clark originally gave to the Snake River.
 

The Columbia River: Gateway to the Pacific

Length: 1,200+ miles | Origin: British Columbia | Mouth: Astoria, Oregon
Stretching more than 1,200 miles to the Pacific, this powerful river cuts through four mountain ranges and carries more water to the ocean than any other river on the continent. Once, it was home to the world’s most prolific salmon runs, with annual returns topping 30 million fish.
On October 16, 1805, Lewis and Clark entered the Columbia River. The river was central to Native economies, especially for salmon fishing.

📝 Clark’s journal, October 17, 1805:

“Large mat lodges of Indians were drying salmon…”
👉 These were the first mat lodges the Corps had ever seen.
👉 "Fish of the Columbia River" 
👉 "Flowers Collected of the Snake & Columbia River"
 

The Yellowstone River: Clark’s Return Route

Length: 554 miles | Explored by Clark: July 1806

While many rivers flow outward from the region surrounding America’s first national park, only one carries the name Yellowstone. Rising in Wyoming’s Absaroka Range just beyond Yellowstone National Park’s southern edge, the river carves a northeast path across Montana before joining the Missouri River in North Dakota.

The Yellowstone River holds the distinction of being the longest undammed river in the lower 48 states—flowing freely through a landscape rich in natural beauty and history.
While Lewis returned via the Missouri, William Clark and his team blazed a new route down the Yellowstone River—retrieving buried caches and crossing Bozeman Pass.

📝 Clark, July 13, 1806: “The Indian woman… recommends a gap in the mountain more south which I shall cross.”
👉 Sacagawea’s knowledge led them safely through what is now Bozeman Pass.

📍 Statue Alert: A powerful bronze of Sacagawea and Pomp marks this moment in Livingston, MT.
 

Trail Treasures & River Facts

✅ Missouri River – Longest in the U.S. at 2,540 miles
✅ Snake River – Once named “Lewis’s River” by the Corps
✅ Salmon River – Still one of America’s last wild rivers
✅ Yellowstone River – Longest undammed river in the lower 48
✅ Columbia River – Lifeblood of the Pacific Northwest salmon culture