Assay Office—Ada County
In the early 1860s, Idaho found itself facing an unprecedented problem; Miners on the Clearwater River had pulled up more gold than the state could afford to send off to the nearest U.S. Mint to authenticate. To resolve the issue, Congress approved the construction of a Boise Assay Office—a Mint without the ability to coin money. By 1872 it was open for business, and would inspect over $400 million in lead, gold and silver before shutting down in 1933. Currently, the site is home to the Idaho State Historical Society, which occasionally offers tours of the building to the curious.
Bear River Massacre Site—Franklin County
One of the bloodiest massacres of Native Americans in U.S. history took when the California Infantry was called in to settle a dispute between the Cache Valley Shoshone tribe and Mormon settlers near Preston, Idaho. Known as The Bear River Massacre of 1863, the conflict is infamous for the number of Native American men, women and children who were killed—estimates range from 255 to 400, a more brutal ratio of dead to living than in Civil War battles of the same time period. Visitors to the spot can stop by a plaque-marked scenic overlook to learn more about its tragic story.
Camas Meadows Battle Site—Clark County
The Camas Meadows Battle Site, located near Kilgore, was a notable point of conflict during the 1877 Nez Perce War, which sparked when the tribe refused to relocate to a reservation. The landmark is comprised of two sites: Camp Calloway, where General Howard paused with his men, and Captain Norwood's encounter site, where the Nez Perce clashed with their U.S. army pursuers. Although the camp is on private land, the encounter site is marked and a sign describing both spots can be found at the Dubois rest stop on I-15.
Cataldo Mission—Kootenai County
Built in 1850 in Coeur d' Alene's Old Mission State Park, the Cataldo Mission enjoys the title of Idaho's oldest building. It was constructed by Jesuit missionaries to serve as a hall of worship for the Coer d'Alene tribe and held unique services that married Catholicism with the tribe's ancestral beliefs, a compromise that brought worshipers flocking in. The site is open to the public year-round and features picnic areas, exhibits and a separate gift shop and museum. If you visit and fall in love, be sure to book the location for your next special event.
Experimental Breeder Reactor No. 1—Butte County
Located between Idaho Falls and Arco, this landmark gives visitors a fascinating look into the early days of nuclear energy. EBR-1 made history on December 20, 1951 when it was nationally recognized as the first-ever power plant to successfully produce electricity from atomic energy. Two years later, another discovery was made with the same reactor—not only could it produce electricity, it could create more fuel than it consumed, making it the first "breeding" reactor in the country. Today, the EBR-1 Museum, open seven days a week, is the only spot in America where you can get a firsthand look at four nuclear reactors.
Fort Hall—Bannock County
Stabbed in the back by his competitors in the fur trade, trapper Nathaniel Wyeth constructed Fort Hall in 1834 so that he could trade directly with Native Americas and cut out the middleman. The fort's prime location on the Snake River's south bank made it a desirable outpost, and it became an HBC trading post, California-Oregon Trail waystation, military post and stop for stagecoaches before falling to a flood circa-1856. Today, what remains is little more than furrows of earth suggesting where walls might have been. For a better idea of what this historic building was like, tour the Fort Hall Replica and museum in Pocatello.
Lemhi Pass—Lemhi County
One of two landmarks Idaho and Montana share, Lemhi Pass is a two-mile road that was home to a pivotal historical moment: there, in the summer of 1805, the Lewis and Clark expedition stepped over the Continental Divide and became the first Americans to enter the hotly disputed western territories. Today, the pass can be reached by road and a parking area provides access to picnic tables, paved trails, interpretive signs and a monument on the divide.
Lolo Trail—Clearwater and Idaho Counties
Like Lemhi Pass, the 160-mile Lolo Trail stretches from Idaho to Montana and is historically significant thanks to a visit from Lewis and Clark. This oft-traveled Nez Perce trail proved a major obstacle on their journey to the Pacific; trapping them for over a week in such heavy snow that their Shoshone guide, Old Toby, lost his way. The trail's terrain is so unfriendly that much of it remains inaccessible today, although the Lewis and Clark Highway (U.S. 12) runs parallel to it in some places, and the occasional marker can be found along the roadside.
Weippe Prairie—Clearwater County
After fighting their way across the Bitterroots, an exhausted Lewis and Clark stumbled onto Weippe Prairie (a.k.a. "Quawmash Flats"), where they were relieved to find a tribe of Nez Perce who fed and housed them on both legs of their journey. Although no evidence of their temporary stay endures, visitors can read about the encounter at a pull-out southeast of Weippe.