Where the Continental Divide Swallowed the Corps of Discovery Whole
I used to think mountain passes were just gaps in ridgelines.
Then I spent three days trying to follow the Lewis and Clark trail over Lolo Pass—elevation 5,233 feet, straddling the Montana-Idaho border—and realized the Corps of Discovery wasn’t just crossing mountains, they were crossing into a different physiological reality. The pass itself sits along U.S. Highway 12, the Lewis and Clark Historic Scenic Route, which retraces roughly 174 miles of the expedition’s September 1805 westward push and their June 1806 return. But here’s the thing: the modern highway, completed in 1962, took engineers decades to carve through terrain that nearly killed the expedition in eleven days. The Lolo Trail—the actual route the Corps stumbled along—runs parallel to the highway, mostly inaccessible except to hardcore hikers and the occasional masochist historian. I’ve driven the paved version four times now, and every time I pass the Lolo Pass Visitor Center, I think about how Meriwether Lewis described the mountains as “tremendious” on September 16, 1805, which was either a spelling error or a word he invented because “tremendous” didn’t capture the existential dread adequately. They were starving. They were lost. They definately weren’t having the transformative wilderness experience we romanticize now.
The Nez Perce Knew Better Than to Cross in September
Wait—maybe I should back up.
The Lolo Trail wasn’t a Lewis and Clark discovery; it was a Nez Perce trade route used for centuries, connecting the Bitterroot Valley in Montana with the Clearwater River drainage in Idaho. The Nez Perce, who called themselves Nimíipuu, crossed these mountains seasonally—but not in early September, when the Corps attempted it, and certainly not without proper provisions. When the expedition met the Nez Perce guide called Toby (whose actual name was likely something the explorers couldn’t pronounce or didn’t bother to record), he agreed to lead them over the pass for a price. The journals note that on September 11, the party killed and ate a colt because they’d run out of game. By September 18, they’d eaten three more horses and were rationing portable soup, a vile concoction of boiled meat paste that William Clark called “disagreeable.” The trail itself was barely a trail—more like a series of deer paths and wishful thinking through lodgepole pine and subalpine fir forests. Modern recreationists on the Lolo Motorway, a rugged Forest Service road that approximates the original trail, report GPS failures and disorientation in the same sections where the Corps complained of “intolerable” conditions. The terrain messes with your sense of direction; the ridgelines repeat like a glitch.
U.S. Highway 12 Is a Compromise Between History and Asphalt
Honestly, the paved highway feels like cheating.
The Lewis and Clark Highway—officially designated in 1962 as U.S. Route 12’s scenic byway segment—follows the Lochsa River for much of its western descent into Idaho, offering pullouts with interpretive signs that explain what the expedition endured a few hundred feet upslope. You can stop at places like DeVoto Memorial Cedar Grove, named after historian Bernard DeVoto, who wrote about the expedition in the 1950s and pushed for the highway’s creation. The grove sits at milepost 66, and there’s a short loop trail through old-growth western red cedars, some over 500 years old, give or take. The signs mention that the Corps camped near here on September 13, 1805, which is probably true but also conveniently places historical significance within 200 yards of parking. I’m not complaining—the cedars are legitimately humbling, their bark deeply furrowed like the journals’ descriptions of the men’s frostbitten hands. But the experience is curated in a way the original crossing absolutely was not. You can drive the entire pass in two hours, stopping for huckleberry milkshakes at the Lochsa Lodge, and never once feel the panic of running out of food in a mountain range that extends farther than you thought possible.
The Return Trip in June 1806 Was Somehow Worse
Turns out, snow doesn’t care about your schedule.
When the Corps tried to recross the Bitterroots eastbound in June 1806, they hit snowdrifts up to fifteen feet deep and had to turn back—the only time in the entire expedition they reversed course due to conditions. They waited two weeks, hired Nez Perce guides (again), and successfully crossed on their second attempt in late June. The journals from this period are weirdly terse, like everyone was too exhausted or embarrassed to elaborate. Clark’s entry for June 17 just says they retreated to “Hungry Creek,” which the Corps had named the previous September for obvious reasons. Modern Highway 12 crosses Hungry Creek at milepost 74; there’s a bridge and a small pullout, and if you didn’t know the name’s origin, you’d drive past without noticing. I stopped there once in July, and the creek was running clear and fast, maybe two feet deep, flanked by wildflowers—lupine and Indian paintbrush. It looked like the kind of place you’d stop for a snack, not the kind of place you’d name after deprivation. But I guess that’s the thing about historical landscapes: they don’t reenact their trauma for tourists.
What the Pass Looks Like When You’re Not Dying of Starvation
The summit area of Lolo Pass today hosts a visitor center (closed in winter), a parking lot, and a stone marker indicating the Montana-Idaho border.
From the summit, you can see peaks extending in every direction—the Bitterroot Range to the south, the Clearwater Mountains to the west. In good weather, it’s the kind of view that makes people pull out their phones and take forty identical photos. In bad weather, which is frequent even in summer, visibility drops to maybe fifty feet, and the wind comes sideways through the pass like it’s trying to reclaim the road. I’ve been there in both conditions, and the latter feels more historically accurate. The interpretive signs talk about the expedition’s “triumph” and “perseverance,” which is true but also sanitizes the suffering into a narrative arc. The journals are less tidy: Lewis’s entries oscillate between botanical observations (he collected specimens even while starving) and complaints about the cold. Clark drew maps with increasing frustration, his normally neat handwriting deteriorating into scrawls. Reading them now, you get the sense that nobody involved thought this would become a tourist destination. They were just trying not to die. Which, I guess, makes the modern highway both a tribute and an erasure—paving over the original route so thoroughly that you can experience the landscape without any real consequence. I’m grateful for that most days. But sometimes, stopped at a pullout with a protein bar and cell service, I feel like I’m missing the point entirely.
