Lemhi Pass, at elevation 7,323 feet above sea level, is a rounded saddle in the Beaverhead Mountains of the Bitterroot Range, along the Continental Divide, between Montana and Idaho. Here, in 1805, the Lewis and Clark expedition first saw the headwaters of the Columbia River, which flow to the Pacific Ocean, and crossed what was then the western boundary of the United States.
Lemhi Pass was designated a National Historic Landmark in 1960 for its significance to the Lewis and Clark expedition. It was a point of hopeful anticipation, as the Corps of Discovery looked forward to meeting the Shoshone and trading for horses to continue their journey, and a point of disappointment as it became obvious that a navigable waterway to the West Coast would not be found among these rugged mountains.
Today, the landscape at Lemhi Pass is very much like it was 200 years ago. You will find native sagebrush and bunch grasses, edged with patches of douglas-fir and lodge pole pine trees. The westward view from Lemhi Pass is of distant ranges of steep, rocky mountains. The weather is generally cool and unpredictable. It can snow at any time of the year. Thunderstorms with lightning, strong winds, and rain or hail are likely in the summer months.
The Forest Service has signs at Lemhi Pass during the summer months, to help tell the story of the pass. Management of Lemhi Pass is intended to maintain the natural, historic landscape. That is why you will not find much development at this site. Lemhi Pass remains a remote mountain pass in a natural landscape, offering motor-vehicle travelers views similar to what Lewis and Clark witnessed on foot and horseback in 1805.
We strongly advise a high-clearance vehicle on the Lemhi Pass road, for some sections may be deeply rutted and others very rocky. You'll want to be sure you have a good spare tire, and equipment to change a tire if needed. The last four miles of road below the pass are quite narrow - a single driving lane. Watch for oncoming traffic and be prepared to use a turnout, or back up if you meet a vehicle. Keep in mind that generally, downhill traffic has the right-of-way.