MY DAD WAS driving down the highway, pumping his fists and singing “My Way” to an old Frank Sinatra tape. The champagne-brown Mercury Sable (premium edition, as he likes to point out) rolled merrily past the endless expanse of chin-high corn and long stalks of prairie grass dancing in the persistent Dakota breeze.

“Stop that crazy noise!” my mom piped up from the back seat, as she often did to get a rise out of dad. Then, turning to my teenage daughter, she added: “You’re lucky. You can tune it out with your iPod.”

“So can you,” quipped my dad. “Just turn down your hearing aids.” The idea, not a new one by any means, always got a laugh.

It was the annual summer road trip and reunion, with four intrepid travelers spanning three generations. This wasn’t for the fainthearted. In fact, my husband and son had opted out years ago. But my dad, mom and daughter found the strength, if not the joy, in continuing this American tradition.

Among the many highlights:

The revelation that two people in the car could be freezing while two others were sure they would die without the air conditioning cranked up too high.

“If you’re cold, put on a sweater,” I suggested with the best of motherly intentions. My teenager was wearing shorts and a tank top that could have been made from two dinner napkins.

“If you’re hot,” the voice from the back seat retorted, “take off something.”

“I can’t. I’m practically naked as it is,” I replied, mildly irritated at the suggestion I might be going through the midlife “change.””Eeeeewwwww!” said the teenager.

“That’s more information than I want to hear,” offered dad.

This kind of scintillating dialogue continued for days as we drove past the red barns and silos and occasional flock of pheasants eating road gravel to digest their food. At night, we took it up a notch.

“Everyone gets one towel,” announced my dad as we checked into our motel room in Jamestown, the home of western novelist Louie L’Amour. This was the Wild West, and Dad was taking charge like the new sheriff in town. He laid down the law about bedtime, too.

“Mom and I are hitting the sack right after the news,” he said firmly. That meant lights out for the teen and the “tweener.”

My daughter resisted, but I reminded her that traveling with the folks was like crossing several time zones, and we’d better try to adapt.

Another revelation: 6 a.m. comes around fast when you’re up half the night reading by flashlight. We had ignored the warning to turn in early the night before and stayed up until midnight. Now we were paying the price as mom turned on the coffee pot just inches from my left ear. Blip … gurgle … drip. It was an ancient water torture mom used to get the family moving and on schedule.

Bismarck by 10 a.m. That was her plan, and there was no wiggle room. My daughter and I shuffled down to breakfast and returned for our predetermined shifts in the bathroom. Dad packed the car with the precision of a puzzlemaker, placing each roller bag in just the right spot in the trunk. It was truly a work of art.

So was the manner in which he drove down the highway to our family reunion in Bismarck, and a second gathering in Aberdeen. Each time he stopped for gas, he calculated the mileage.

“We’re getting 31 miles to the gallon,” he would announce with the pride of a traveling salesman.

It was comments like these that used to slip past me. I’d spend much of my time reading or sleeping on the Dakota road trips of my youth.

But now, I’m keenly aware of time fading away. Each year, it gets harder for my parents to make the trip. Relatives are growing old, and towns like Eureka, my birthplace, are struggling to survive.

“This could be our last trip out here,” Dad said, matter-of-factly. I wonder if it’s true. Then I realize the laughter and the lessons we’ve learned about family love and patience will never die. The memories of these Dakota road trips will stay with us long after my dad’s Mercury Sable logs its last mile.