I remember visiting Yellowstone in second or third grade, a rare and wonderful trip with my grandparents in their trailer, tromping on the boardwalks past bubbling, smelly hot pools of who-knew-what, perching on the castle-like stone walls to feed chipmunks, watching Old Faithful spew out of a hole in the ground.

My sister and I loved the Morning Glory Pool, a beautiful azure hot spring in the shape of the delicate flower, and Nancy got a charm of it for her bracelet, silver with a clear-blue center.

But mostly I remember the bears. They were everywhere. Even in the campground. I remember one pawing at the toe of my tennis shoe, begging for a handout.

When I woke up in the primitive campground in South Dakota’s Badlands National Park, I raised the window shade to see a bison lying about 100 yards away. He lazily munched on grass, and then, as the air warmed, lumbered to his feet and wandered off.

We have seen bison all across the plains – Texas, Kansas, South Dakota – but usually behind fences or, stuffed, in museums. Here, in the Badlands and in Custer State Park, they roam freely, grazing, scratching their backs against tree stumps, meandering across roadways, glancing, with little interest, at the cars.

Bison, whose ancestors came across the Bering land bridge from Siberia are, perhaps, the most American of all iconic wildlife.

Some of my mother’s first memories are of a trip with her parents to see Mount Rushmore under construction. It was 1933. She was just three years old.

The tornado siren on my iPhone went off as I sat in The Epic Van, a slight sprinkle pattering on the roof. The storm app showed a red line around Nebraska’s Webster County, now under a tornado watch. It meant the angry storm lines on the radar, green bands with yellow centers and red spots, were capable of “firing” funnel clouds.

The gypsum dunes at White Sands National Monument have a timeless quality, endlessly shifting and moving, an inspiring white expanse that quiets the mind and makes other vistas and landscapes seem annoyingly busy.

When Tom and I drove up, I was hit by a wave of nostalgia for our son, Nate.

On our recent tour of the Heart of the Desert Pistachio grounds and processing plant, we got up close and personal with the nuts and learned:

The first view I have of the City of Rocks immediately reminds me of the trip Tom and I took to Stonehenge in England. But man had no hand in the striking formations that rise out of the New Mexico desert.

This geological oddity is the result of volcanic ash spewed out 30 million years ago, piled up, buried and pressed into rock, then pushed back to the surface, where wind and water carved it into wild looking obelisks, teetering sculptures and mushroomlike stands.

They stood watch in a missile silo, next to an immense projectile carrying a nine-megaton nuclear warhead, waiting for the call to launch. The crews assigned to Titan Missile silos were standing on the brink of madness we approached during the Cold War.

The Titan Missile Museum outside Green Valley, Arizona, is an eerie reminder of the era of mutually assured destruction, as the United States and Soviet Union aimed even nuclear firepower to annihilate the world many times over.

For us, it carries even more significance because one of Tom’s friends since high school served in a silo near McConnell Air Force Base in Wichita, Kansas.