The two-year expedition of Meriwether Lewis and William Clark from the Mississippi River to the Pacific Ocean and back got under way in May 1804 in Missouri, then the western edge of the United States, and ended when the Corps of Discovery, as President Thomas Jefferson named it, returned to St. Louis in September 1806. The explorers gathered new information about the West, its people, animals, geography, vegetation, rivers and lakes. The explorers described in detail the Missouri and Columbia rivers, the Indians who lived along their shores, and, in the Columbia drainage, abundant salmon.

Officially, so as not to offend Spain, whose possessions were to the southwest of the Missouri River, or Great Britain, whose possessions were to the north of it, the expedition was a scientific and literary expedition, despite the fact that Lewis and Clark were U.S. Army officers and most of their 43 men were soldiers. The true purposes, however, were commercial and political. Jefferson, who conceived the expedition, sought to beat Great Britain to the western fur trade by finding a water route across the continent to the Pacific Ocean.

Publicly, Jefferson’s intent for the cross-country exploration was to enhance geographic knowledge of the West. Privately he aimed to expand the United States and wrest the fur trade from the British. In his January 1803 request to Congress for $2,500 to finance the expedition, he couched his intent in terms of promoting commerce, which was within the powers granted Congress in the Constitution. He wrote that the Indians of the Missouri River drainage supplied furs “to the trade of another nation” — an obvious reference to Great Britain — and that the United States would do well to know these tribes better. He theorized that the Missouri might provide a better transportation route to the Pacific for this commerce.

Thus through westward expansion, the United States would usurp the fur trade from Great Britain. Jefferson wrote, in part: “...The interests of commerce place the principal object within the constitutional powers and care of Congress, and that it should accidentally advance the geographical knowledge of our own continent can not but be an additional gratification.”

A month before his March 1801 inauguration, Jefferson had appointed Lewis, then 26, his personal secretary. It appears, although this is a matter of dispute among historians, that Jefferson had been grooming Lewis for command of the expedition ever since. In his June 20, 1803, instructions to Lewis regarding the exploration, Jefferson wrote:

“The object of your mission is to explore the Missouri River, and such principal stream of it, as, by its course and communication with the waters of the Pacific Ocean, whether the Columbia, Oragan [sic], Colorado, or any other river, may offer the most direct and practicable water-communication across the continent, for the purposes of commerce.”

The Columbia, as Lewis and Clark discovered, is not a principal stream of the Missouri. That did not matter. The goal was not the headwaters of the Missouri but the Pacific Ocean. Historian Bernard DeVoto wrote that Jefferson already had decided to send an exploratory mission west across then-Spanish Louisiana when he took office in 1801. To the expansionist Jefferson, the exploration would knit together the eastern and western ends of the American continent, if tenuously.

The Columbia River was virtually unknown in 1804. Robert Gray had discovered it only 12 years earlier. Jefferson imagined that the portage between the headwaters of the Missouri River, which drained east to the Mississippi, and the headwaters of the Columbia, which drained west to the Pacific, would be only a short distance, easily portaged by fur caravans. In fact, as Lewis and Clark discovered, it is not a short portage and it is not at all easy.

The Corps of Discovery crossed the Continental Divide in August 1805, some 15 months after beginning their westward journey, and entered salmon country. On August 13, at a camp of Lemhi Shoshone Indians in the mountains of present-day central Idaho, Lewis wrote, “An Indian gave me a piece of fresh salmon roasted, which I ate with a very good relish. This was the first salmon I had seen, and it perfectly convinced me we were in the waters of the Pacific Ocean.”

The explorers would record other observations of Lemhi salmon. Clark noted that salmon were a principal food for the Indians: “ man killed a Small Sammon, and the Indians gave me another which afforded us a Sleight brackfast. These Pore people are here depending on what fish they can catch, without anything else to depend on.”

Upon learning that the Lemhi River drained to the Salmon (their present-day names), and that the canyon there was too difficult to pass, the expedition followed a trail into the next drainage north, that of the Clearwater River. Here the expedition encountered Nez Perce Indians. Now the men ate salmon regularly, and so frequently that they tired of it. The expedition followed the Clearwater to the Snake and the Snake to the Columbia. Upon reaching the Columbia in mid-October, Clark was impressed by the sheer numbers of salmon:

“I took two men in a Small canoe and ascended the Columbia river 10 miles [from the confluence with the Snake River] to an Island near the Stard. [starboard: right, or north side, in this case] Shore on which two large Mat Lodges of Indians were drying Salmon. The number of dead Salmon on the Shores & floating in the river is incredible to say — and at this Season they have only to collect the fish Split them open and dry them on the Scaffolds of which they have great numbers.

“...Saw great numbers of Dead Salmon on the Shores and floating in the water, great numbers of Indians on the banks and viewing me and 18 canoes accompanied me from the point. The waters of this river is clear, as Salmon may be seen at the deabth of 15 or 20 feet. . .passed three lodges on the Star. Side near which great number of Salmon was drying on scaffolds. One of those Mat lodges I entered and found it crouded with men women and children and near the entrance of those houses I saw maney squars engaged in Splitting and drying Salmon.”

As Clark and his party returned downriver they passed more villages and noted “great numbers of Dead Salmon on the Shores and floating in the water, great numbers of Indians on the banks viewing me. . .” At one village, the party stopped and entered a lodge constructed of rush mats. It was “crouded with men and women and children.” The Indians boiled salmon for their guests in baskets of water, into which they had placed rocks heated in a fire. The boiled fish, Clark noted, “was delicious.” The Indians also gave the explorers gifts of several fish.

After the brief foray up the Columbia from the confluence of the Snake, Clark wrote that was little wood in the area, and that much of what the tribes had appeared to have floated down the river from places upstream. About the Indian dwellings he observed:

“The Houses or Lodges of the tribes of the main Columbia river is of large mats made of rushes, those houses are from 15 to 60 feet in length generally of an Oblong squar form, Supported by poles on forks in the in[n]er Side, Six feet high, the top is covered also with mats leaving a Seperation in the whole length of about 12 or 15 inches wide, left for the purpose of admitting light and for the Smok of the fire to pass which is made in the middle of the house.”

Later, descending the Columbia, the explorers noted the abundance of salmon at Celilo Falls, the great Indian fishery about 13 miles upriver from present-day The Dalles, Oregon. Here the river tumbled over a series of low falls, which afforded easy access to Indians fishing with dip nets mounted on long poles. Clark noted that the Indians would dry the fish, pound it flat and pack it into baskets that he estimated weighed 90 to 100 pounds apiece. “Thus preserved those fish may be kept Sound and Sweet Several years, as those people inform me, Great quantities as they inform us are Sold to the whites peoples who visit the mouth of this river as well as the nativs below.”

Typically, the baskets were stacked together in groups of 12, seven on the bottom and five on top. Each basket was about two feet long and one foot in diameter. Salmon, dried and pounded flat, were pressed into the baskets, which were lined with stretched and dried salmon skins on three sides. When a basket was full, it was covered with stretched salmon skins, and these were tightly secured. The baskets then were stacked in a dry place and covered with grass mats. Lewis and Clark counted 107 of these stacks at The Dalles weighing, in total, an estimated 50 tons.

At the Long Narrows of the Columbia, near present-day The Dalles, the channel of the Columbia narrows and the river flows through a series of long basalt chutes bordered by high basalt cliffs on both shores. This area was flooded in 1957 by the reservoir behind The Dalles Dam. But in 1805 the place was foreboding, as Clark described in his diary for October 24. He determined that a portage over the cliffs would be impossible, and so the only alternative was to risk the agitated water:

“The whole of the current of this great river must at all Stages pass thro’ this narrow channel of 45 yards wide. as the portage of our canoes over this high rock would be impossible with our Strength, and the only danger is passing thro those narrows was the whorls and Swills. . .by good Stearing we could pass down Safe, accordingly I deturmined to pass through this place notwithstanding the horrid appearance of this agitated gut Swelling, boiling & whorling in every direction (which from the top of the rock did not appear as bad as when I was in it; however we passed Safe to the astonishment of all the Inds . . .”

It is a tribute to the skill of the boatmen that they were able to maneuver through the rapids and emerge safely below. The Indians, Clark noted, were astonished by the feat. The expedition was fortunate to reach this place in the late fall. In the spring, during the annual freshet, the water route likely would have been impossible.

At Fort Clatsop, near present-day Astoria, Oregon, where the Corps of Discovery spent the winter of 1805-06, Lewis had time to write more of his reflections in the journal of the expedition. On January14th he reminisced about salmon:

“From the best estimate we were able to make as we descended the Columbia, we conceived that the natives inhabiting that noble stream, for some miles about the great falls to the grand rappids inclusive annually prepare about 30,000 pounds of pounded sammon for market, but whether this fish is an article of commerce with the whites or is exclusively sold to, and consumed by the natives of the sea coast, we are at a loss to determine.”

Lewis assumed the pounded, dried fish was bartered primarily to European fur traders. He wrote: . .still I must confess that I cannot imagine what the white merchant’s object can be in purchasing this fish, or where they dispose of it.

The local Indians had great quantities of dried fish, which they caught in the nearby rivers and inlets, Lewis noted, “. . .and I have never seen this pounded fish in their lodges, which I presume would be the case if they purchased this pounded fish for their own consumption. The Indians who prepared this dryed and pounded fish, informed us that it was to trade with the whites, and shewed us many articles of European manufacture which they obtained for it.”

Lewis surmised that the Celilo fishers obtained the European trade goods from coastal tribes, who had received them in trade with European fur traders. He assumed that the coastal tribes then consumed some of the dried fish themselves and traded the remainder to other coastal tribes in exchange for the trade goods. This scenario was confirmed for him by Indians who visited on January 20th, and Lewis noted the fact in the journal: “The Indians who visited us today understood us sufficiently to inform us that the whites did not barter for the pounded fish; that it was purchased and consumed by the Clatsops, Chinnooks, Cathlahmahs and Skillutes.” The trading among Indian groups, the location and the broad, deep river convinced Lewis and Clark that the mouth of the river would be a good place for a trading post to service the cross-country and cross-ocean trade that Jefferson envisioned.

The explorers hoped they might encounter a trading ship in the Columbia estuary so they could send some of their accumulated materials home and acquire a supply of trade goods for the return journey. But no ship arrived, and the party abandoned Fort Clatsop on March 23, 1806. A month or so later, a Russian trading ship tried unsuccessfully to cross the Columbia bar. On board was Nicolai Rezanov, co-founder of the Russian-American Company, a fur-trading enterprise based at Sitka. Rezanov envisioned a Russian settlement at the mouth of the river, but it never came to pass. At the time Rezanov’s ship waited in vane for calm conditions on the bar, Lewis and Clark were near the confluence of the Willamette and Columbia Rivers on their eastward return journey about 80 miles upriver. Rezanov sailed on to California.

Lewis and Clark observed more salmon fishing on their return journey. Clark’s journal entry for April 6, 1806, when the party again was near Celilo Falls, notes: “We observed many stacks of fish remaining untouched on either side of the river. This is the great mart of all this country. Ten different tribes visit those people for the purpose of purchasing their fish...” And on April 19, also at Celilo, Clark wrote: “There was great joy with the natives last night, in consequence of the arrival of the salmon. One of those fish was caught. This was a harbinger of good news to them.”

A month later, reflecting on the potential of the area today known as the Columbia Plateau, Lewis wrote, “... this country would form an extensive settlement; the climate appears quite as mild as that of similar latitude on the Atlantic coast if not more so, and it cannot be other wise than healthy; it possesses a fine dry pure air. the grass and many plants are now upwards of knee high. I have no doubt but that this tract of country if cultivated would produce in great abundance every article essentially necessary to the comfort and subsistence of civilized man.”