Distinctly Montana Magazine

42 D I S T I N C T LY M O N TA N A M A G A Z I N E • S P R I N G 2 0 2 6 P ULL UP MONTANA'S 1864 TERRITORIAL MAP AND YOU'LL SEE MARIAS PASS PROMINENTLY MARKED. It is the lowest route through the Rocky Mountains in the United States, cresting the Continental Divide a hair less a mile above sea level. It is an excellent railroad pass, with a gentle slope on the east side and a riv- er-grade route down the west side. Other than a few shortcuts through river bends, no pesky and expensive tunnels are needed. The only problem is the map is wrong. Other than Native Americans and fur traders, no one knew where the rumored pass was located in 1864. And its location would not be found for nearly four decades. Under orders from a railroad president blindly pushing tracks across northern Montana toward the mountains, a lone surveyor would ven- ture out in minus 40 degree weather and finally nail down its location. Marias Pass is named after a river, which in turn is named after the cousin of Meriwether Lewis. Lewis, of Lewis and Clark fame, suppos- edly had a romantic interest in young Maria Wood. The apostrophe was soon purged from Maria's River, giving the current name. On its way to the Pacific in 1805, the expedition ground to a halt at the confluence of the Marias and Missouri Rivers, at present-day Loma, Montana. The issue was deciding which river was which, since the two had equal flows. Finally they concluded the Marias—the muddiest of the two—was swollen by spring runoff, and the correct route was south. The decision led them to the headwaters of the Missouri. But also took them into the wilderness of Idaho, an abortive encounter with the River of No Return, and a struggle over Lost Trail Pass back into Montana. On the return trip in 1806 the expedition split and Lewis slipped across the Continental Divide near Lincoln, Montana. He was headed back to the Marias River to see if it led to the beaver-rich muskeg country of Canada. It didn't. The continental glacier of the Ice Age had bulldozed south to roughly the present U.S.-Canada border. The Hudson Bay Di- vide is a barely noticeable hill extending east from St. Mary in Glacier National Park. But it is substantial enough to leave the Missouri and oth- er rivers no choice but to flow toward the Mississippi. At first the Marias River headed promisingly north, but it soon turned west. Lewis gave up just past Cut Bank, and headed back toward the Missouri, and a resulting race for his life after a fatal encounter with Blackfeet. But, at what he called Camp Disappointment, Lewis had been looking di- rectly at Marias Pass. It would remain unexplored for another 84 years. The pass was largely ignored until 1853, when Isaac Stevens, the ter- ritorial governor of Washington, headed across the northwest to slap a series of treaties on the local tribes. The hasty treaties, mostly aimed at securing railroad routes, would come back to haunt both sides in future generations. But, as part of his efforts, he launched expeditions to locate potential routes across the Rockies and Cascades. Abiel Tinkham was assigned to find the pass. Everyone knew it was somewhere between the Middle Fork of the Flathead River and the Two Medicine River, about 50 miles south of the Canadian border. Tinkham headed up the Middle Fork and turned west at Nyack up a promising valley. by RICK HULL The Mystery Pass of the Northern Rockies

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