Three Options
Clark sent a private on horseback with a note to Lewis stating three possible plans for their route to the ocean. The first was to procure one horse for each man, hire Toby as a guide, and proceed by land to some navigable part of the Columbia. The second plan was to divide the men into two parties, make dugouts, and have one party attempt the treacherous Salmon with whatever provisions were on hand while the remaining party would go by horseback, procuring what food they could by use of their guns, and occasionally meeting up with the party on the river. A third possibility would be to divide into two parties, have one go over the mountains to the north while the other returned to the falls of the Missouri to collect provisions, go up Sun River, and over the route used by the Hidatsas to get to the country of the Flatheads (near present Missoula). Both parties would meet there and continue on to the ocean.

On Aug. 26, Clark's messenger arrived at the Shoshone village with the note about the same time Lewis arrived. Clark recommended that the first plan be used, and that a horse be purchased for every member of the Expedition. The chief, however, informed Lewis that the Pahkees had stolen many of their horses that spring and that they could not spare that many.

Lewis sent word for Clark to come to the village and get the 22 horses he had been able to purchase. Clark managed to purchase another horse for his pistol, 100 balls, powder, and a knife. Another horse was bought for a musket.

The explorers set out with Toby as their guide, and soon began their ascent of the North Fork. Two days later they found the mountains close to the creek on both sides. They were forced to travel along the steep mountain walls. Several of the horses slipped and injured themselves quite badly. It was also at this place that they had the misfortune of breaking their last thermometer. It snowed about two inches, then began to rain, and then sleet.

Shortly before reaching Lest Trail Pass, Toby, for some unknown reason, led the party in the wrong direction. They encamped that evening about three miles west of the pass, having taken a much more difficult route than necessary.

The Bitterroot Valley and the Flathead Indians
On the morning of Sept 4, everything was wet and frozen, and the ground covered with snow. They went over the crest and down the other side of the mountain range, a distance of about twelve miles, where they met a village of the Flathead nation—33 lodges, some 440 people, and 500 horses.

Lewis and Clark were able to purchase 13 more horses from the Flatheads. On Sept. 6, they set out down the Bitterroot River and reached the wide valley of that river on Sept. 7. They passed down the valley with no peculiar incident until they reached Lolo Creek. They named their camp Travellers Rest.

Toby informed the captains that if they continued down the Bitterroot about nine miles to the Clark's Fork, go up that river to the Blackfoot River, and then on to the Great Falls, they were only four days from the Missouri. He also told them that they were now to leave the Bitterroot River and turn west up Lolo Creek on the Nez Perce trail.

One of the hunters met three Flatheads up Lolo Creek and brought them back to Travellers Rest. One of them agreed to accompany the Expedition as a guide over the Bitterroots, and introduce them to his people who lived on the other side at a place where they could build dugouts and sail to the ocean.

To the Ocean
On Sept. 11, the explorers set out again, and two days later reached Lolo Pass. On the 14th, they began what was to be the most difficult part of their entire journey. Horses fell on the steep trail, one nearly 100 yards down the mountainside. There was no game and they were forced to eat candles, horses, and their insipid "portable soup." There were times when they had no water. At other times there was nothing at all to eat. Poor diet caused the men to weaken and sores developed on their bodies. In spite of these hardships, they eventually reached the Nez Perce on the Clearwater River. They left their horses with these people, made another cache, built five dugouts, and navigated the Clearwater, Snake, and Columbia rivers until finally, in November, they reached the Ocean.

They built a winter fort near the coast and christened it "Fort Clatsop" in honor of their neighbors, the Clatsop Indians.

On March 26, 1806, the Expedition began its return up the Columbia on the homeward journey. They collected their horses from the Nez Perce, and on June 30 arrived back at Travellers Rest.

The Return Journey

Clark Explores Yellowstone
At Travellers Rest, on July 3, the party separated. Clark with 50 horses, 20 men, Sacagawea, and her baby, headed up the Bitterroot River to the place they had met the Flatheads the year before. They then crossed the Continental Divide at Gibbon's Pass; crossed the head of the Big Hole valley in a southeasterly direction, passing a place where the Indians had recently been digging roots; stopped at a hot springs; crossed Big Hole Pass; and arrived at Camp Fortunate on July 8. Here they recovered their dugouts and the supplies that had been cached the year before.

After reaching the Three Forks, Sergeant John Ordway and nine men continued down the Missouri with the dugouts. Clark and the rest of the party headed east along Gallatin River on to explore the Yellowstone River. Clark crossed Clark's Pass, and hit the Yellowstone near present Livingston. Unfortunately all of Clark's horses, which were to be used for trade at the Mandan villages, were stolen by Crow Indians who were never seen.

Lewis Explores the Marias
From Travellers Rest, Lewis and nine men headed down Bitterroot River to the Clark Fork. They crossed that river and headed upstream to Blackfoot River, which they ascended, following the route to the plains used by the Nez Perce on their buffalo hunts.

On July 6, they crossed "the prairie of the knobs"; Lewis identified the path they were following as a warpath of the Hidatsas. They passed the remains of many Indian ledges, and crossed the Continental Divide at Lewis and Clark Pass. The next day they saw the first buffalo since entering the mountains a year earlier. Two days later they reported seeing 10,000 buffalo in a 2-mile circle. They reached Sun River, and followed it to their upper portage camp at the Great Falls.

As with Clark's horses on the Yellowstone, seven of Lewis's horses were stolen by Indians who were never seen.

On July 16, Lewis and three men set out overland from the Great Falls to explore Marias River. They wanted to see if it reached 50 degrees north, thus determining the northern boundary of the Louisiana Territory, and satisfying the conditions of the 1783 U.S. Treaty with England.

On July 18, Ordway's party arrived at the Great Falls with the boats that would be portaged to below the falls.

Also on the 18th, Lewis's party reached the Marias. Three days later they reached the headwaters of the Marias, and headed up the northern branch (Cut Bank River). They finally came to a place where they could see the river exiting from the mountains. Because the river did not reach 50 degrees north, Lewis named his camp "Camp Disappointment." It was the northernmost camp of the entire Expedition. Lewis was hopeful that the Milk River would reach the 50th Parallel, but he wouldn't have time to check it out.

On their return to the Missouri River, Lewis' party met eight Blackfeet Indians. From them Lewis learned that a large band of their tribe was on its way to the mouth of Marias River. The Indians camped with Lewis's party on Two Medicine River were awakened when the Blackfeet Indians attempted to steal their horses. In the ensuing fight, two of the Indians were killed.

Lewis' party made a hasty retreat to the Missouri River where they had the good fortune of meeting the boats coming down the river from the Great Falls. They abandoned the horses, boarded the boats, and sailed down to the mouth of Marias, picked up the items they had cached the year before, and took off before any Blackfeet arrived.

The Rendezvous and the Home Stretch
Lewis and Clark met again on the Missouri River on Aug. 12, about 125 miles below the mouth of the Yellowstone. They left the Charbonneau family at the Mandans, and continued on down the Missouri, arriving at St. Louis on Sept. 23. They had traveled over 8,000 miles and had successfully accomplished their mission. They found the most practicable route to the ocean; discovered numerous plants and animals for science; made friends with many Indian tribes; and, for the first time, charted a route across the Trans-Mississippi West.