Mullan, Idaho — Interstate Follows a Road Older Than Idaho

Mullan sits near the Idaho-Montana line in a mountain corridor people have been engineering for transportation since before Idaho Territory existed.

Army officer John Mullan supervised construction of a wagon road across the northern Rockies beginning in the late 1850s. His route crossed the Bitterroots through the pass that now carries his name.

Mining later gave the town below a reason to stay.

Silver, lead and zinc operations pushed into the surrounding mountains, while houses, rail lines and roads competed for limited canyon floor.

Modern Interstate 90 climbs through the same basic corridor toward Lookout Pass.

Wagons, railroads and automobiles all arrived at the same conclusion: there are only so many sensible ways through these mountains.

John Mullan's version was slower.