The journey changes. On July 25, 1805, the Corps determine they have reached the Missouri's headwaters, near what is now Three Forks, Montana. They follow one fork, the newly named Jefferson, southwest. But without the Missouri to guide them, they lose certainty. A confusing maze of mountains rises to the west.
There is another change. As the Corps cross the Montana plains, they encounter none of the native peoples who live there. The Assiniboins and Blackfeet surely know of the strangers' presence. But they choose not to reveal themselves.
Now the stories of the mountains and the peoples who live in them intertwine. The Corps' 15-year-old interpreter, Sacagawea ― the most widely used spelling, although some prefer "Sacajawea" instead ― begins to recognize landmarks. Here is home: the country from which she was kidnapped five years earlier. On August 17, Lewis, who had been traveling ahead of the main party, escorts a group of Lemhi Shoshone back to the site the Corps have dubbed Camp Fortunate.
The account of this meeting still brings a lump to the throat. Sacagawea, Clark recorded, "danced for the joyful Sight, and She made signs to me that they were her nation." She had found her people. One of them, Chief Cameahwait, was her brother. ("A man of Influence, Sence, & easey & reserved manners," praised Clark, as if the chief were a marriageable hero out of Jane Austen.) Cameahwait sold the expedition needed horses, lent them a guide, whom the captains called Old Toby, and offered invaluable advice about proceeding west.
So, let Sacagawea and her people be your guides through their part of the world. Start near Three Forks in Missouri Headwaters State Park, still remarkably unspoiled, then take Interstate 90 and State 41 south to the college town of Dillon, Montana, where you can admire the old- fashioned diorama of the Corps at the town's visitor center. Drive south on Interstate 15 to the site of Camp Fortunate, now submerged beneath Clark Canyon Reservoir.
Part of the fun of following Lewis and Clark is the chance to drive backroads. Here's a superlative one: Head east on State 324, south on Forest Road 3909, then drive up Lemhi Pass Road through deceptively gentle hills to 7,373-foot-high Lemhi Pass. (The dirt-and-gravel road is generally open June to October ― check before you set out ― and is suitable for passenger cars.) At the crest of the Continental Divide, you'll see one of the West's most breathtaking views: to the west, ridge upon ridge of mountains; to the east, the full sweep of prairie Montana. Then you follow steep, curvy Agency Creek Road down into Idaho's Lemhi River Valley.
Last year, Salmon, Idaho, opened the Sacajawea Interpretive, Cultural, and Education Center. Exhibits and an interpretive trail tell the story of the heroine and her tribe. "Sacagawea is mythical, almost," says center director Gary Van Huffel. "But the Lemhi Shoshone feel her strength comes from her Shoshone upbringing."
From Salmon, take U.S. 93 north over Lost Trail Pass, then drop down into Montana's Bitterroot Valley. At Travelers' Rest State Park, archaeologists have discovered interesting if ignoble traces of the expedition: mercury deposits in the camp latrine, remnants of the Corps cure-all, Dr. Benjamin Rush's Thunderclappers.
Now west again, up U.S. 12 to Lolo Pass. Here is another case where the gap between the Corps' experience and ours widens into a chasm. Struggling over the Bitterroots in September of 1805, Lewis and Clark endured fierce hunger and brutal weather: "I have been wet and as cold in every part as I ever was in my life," wrote Clark.
Today the drive is pure beauty. The highway climbs mountainsides veiled by mist, solemn with cedars, with silver streams ― Lolo Creek, Lochsa River ― shining below. An adolescent black bear tumbles across the road ahead, clowning, oblivious, before vanishing into forest.
In a few hours, you reach Weippe Prairie. Perhaps it is a mistake to oversell this site, one beloved by Lewis and Clark enthusiasts. There is not that much to do here. The town of Weippe has opened an interpretive center that features murals of the expedition; out on the prairie proper, you can see a large sign that explains what took place here.
And yet Weippe Prairie is one of the most evocatively beautiful places anywhere along the trail: a high rolling plain, seemingly suspended between earth and cloud. Here, on September 20, a nearly starving Clark staggered out of the mountains to encounter members of the Nez Perce tribe. According to oral tradition, one was an elderly woman named Watkuweis, who advised her suspicious fellow tribe members not to kill the newcomers but to treat them well.
In this way, Lewis and Clark's travels through the harsh mountains are bookended on the west and east by striking examples of Native American generosity. In Lapwai, Idaho, tribe member Ethel Greene is in charge of the Nez Perce's participation in the Lewis and Clark bicentennial. It has not been easy, Greene says, to share a story that holds such a strongly mixed message. After all, many of the strangers who came after Lewis and Clark were noticeably less benign.
Lewis and Clark's bicentennial, Greene says, "is not a celebration to us. It is an observance. Remember, if we had not allowed them to come in, if we had killed them, well, that would have changed everything."