MARSHALL AND SYLVIA HOTLE, WHO LIKED TO LIST THEIR places of residence as Cedar Rapids, Iowa, Quartzsite, Arizona, and “the open road,” were preparing dinner when they saw the dark SUV with Illinois plates drive by on the access road for the third time in less than an hour.

“There they are again,” Sylvia said, narrowing her eyes. She was setting two places on the picnic table. Pork cutlets, green beans, dinner rolls, iceberg lettuce salad, and plenty of weak coffee, just like Marshall liked it.

“Gawkers,” Marshall said, with a hint of a smile. “I’m getting used to it.”

The evening was warm and still and perfumed with dust and pine pollen particular to the Black Hills of South Dakota. Within the next hour, the smell of hot dogs and hamburgers being cooked on dozens of campground grills would waft through the trees as well. By then the Hotles would be done eating. They liked to eat early. It was a habit they developed on their farm.

The Hotles had parked their massive motor home for the night in a remote campsite within the Mount Rushmore KOA complex near Palmer Gulch, only five miles away from the monument itself. Because it was late August and the roads teemed with tourists, they’d thought ahead and secured this choice site-one they’d occupied before on their semi-annual cross-country trips-by calling and reserving it weeks before. Although there were scores of RVs and tents setting up within the complex below, this particular site was tucked high in the trees and seemed almost remote.

Marshall often said he preferred the Black Hills to the Rocky Mountains farther west. The Black Hills were green, rounded, gentle, with plenty of lots big enough to park The Unit. The highest mountain-Harney Peak-was 7,242 feet. The Black Hills, Marshall said, were reasonable.