Question: What mountain range was crossed by the wagon road that connected Fort Walla Walla to the fort established in 1846 in Montana?
Sentence (from "Fort Benton, Montana"): Established in 1846, a full generation before the U.S. Civil War, Fort Benton is one of the oldest settlements in the American West; in contrast, many other places—including large cities today—were settled in the late 1860s, 1870s, or 1880s.
Relevant evidence: Yes