OF COURSE, MY WAITRESS FRIEND back in Vegas had a point. There's a time for everything, and at the end of my road trip I decide it's time for the Strip. On my last night in Nevada, I ride the Rio All-Suite Hotel and Casino's elevator up to the top floor, the 51st, to the VooDoo Cafe & Lounge. I gorge on crab cakes, crispy coconut-battered shrimp, and "hellfire" hot wings.

The waiter suggests a VooDoo Blue, a $10 vodka drink, and I tell him to bring me one in a hurry. After dinner, I walk onto the rooftop patio to finish it and catch some air. The desert heat mugs me.

Nevada is not unknowable, but it is stubborn about revealing itself. My odometer testifies to that: I've driven 3,000 miles and hiked and biked hundreds more.

A thousand feet up, I see the city, animated by swarms of pinks, blues, yellows, and greens—every bright color you can imagine—with armies of cars and taxies pumping through this weird creation's veins and arteries. The VooDoo Blue is having its promised effect, and I stand there against the railing, soaking in the rays from below.

I think back on all the places I visited—and all the places that I don't have time to tell you about, such as Ash Meadows National Wildlife Refuge and Amargosa Dunes. Nevada is not unknowable, but it is stubborn about revealing itself. My odometer testifies to that: I've driven more than 3,000 miles, eaten countless homegrown steaks, and hiked and mountain-biked hundreds of miles.

My eyes move to the edges of the city, where the lights fizzle out and disappear into blackness. That, I know, is where the coyotes, mountain ranges and basins, petroglyphs, and jackrabbits begin. The term mysterium tremendum pops into my mind, learned from a recorded lecture by climber and philosophy professor Willi Unsoeld, member of the first team of Americans to climb Mount Everest. It refers to the simultaneous feeling of awe and dread one experiences when confronted with the tremendous power of nature or, for some people, God. It might happen when you're facing rapids that are beyond your comfort zone. Or maybe it's a tiny yellow flower peeking through a dark, ice-covered climbing wall thousands of feet off the ground. In my case, it's the entire state of Nevada.