The old school bus rumbles to life with a painful metallic grinding and we roll forward, our chariot rocking side to side down a rutted, muddy street of a small crossroads town called Dumre in central Nepal. Angling down a hillside, the bus lists heavily to starboard and moves too slowly to escape its own cloud of choking exhaust, which drifts in through the open windows.

Venture into the engine house at Golden Spike National Historic Site and you'll walk into the past, surrounded by steam engines and the men that keep them running.

We’re just seconds beyond the sign at the start of the Gunsight Pass Trail that reads “Entering Grizzly Country” when Nate, who’s a month shy of his tenth birthday, begins aggressively making the case for why he should be armed.

From our snowy perch on Mather Point on the South Rim, the majestic formations of the Grand Canyon rise from the shadowy abyss below us. The morning sun washing through the canyon breaks the winter chill and saturates the reds, yellows, and oranges of the crests, buttes, and sinuous ridges. Gleaming in the morning’s warm light, the formations morph from distant cardboard cutouts into cosmic monuments and temples.