I recently came home to find my wife staring out the window.

“Look at Bella,” she whispered.

Bella, our dog, was sitting on the deck and staring intently at the lawn. Out on the lawn, our cat, Sparkles, was staring intently at a gopher hole.

You know it’s time to go on vacation when you’re watching your wife who’s watching the dog who’s watching the cat who’s watching a gopher hole.

So, we headed for the hills. Specifically, the Black Hills, where we met up with our son and daughter-in-law and their kindergartener son.

Our first stop was Reptile Gardens, where we viewed a very large and diverse collection of tourists. There were also a good number of reptiles on display; many of them were either large and dangerous or small and venomous. In other words, it was much like working in a corporate office.

Among Reptile Garden’s biggest draws are their giant tortoises, one of which had just turned 121. We tried to impress upon our grandson that the tortoise was much, much older than grandpa and grandma but he didn’t buy it. Especially regarding Grandpa.

The next morning, we drove to the Mammoth Site in Hot Springs. We gaped in wonder at the ginormous fossilized skeletons of the gargantuan elephants that once roamed the continent. When I told our grandson that some of the bones were more than 140,000 years old, he implied that I had been around when the fossils were laid down. I was going to buy a carbon dating kit to prove that this wasn’t the case, but it was time to leave.

Our next stop was Evans Plunge, where I had to face my ancient archenemy: water.

Not all water scares me. Just any water that’s deeper than my ankles.

The pool at Evans Plunge is pleasantly warm, but it’s also unpleasantly deep. It often reached my shoulders, which is alarmingly close to the body part that needs to breathe.

Our grandson swims like a minnow. He tried to teach me how to swim, instructing me to kick my legs. I did so and it raised up the back end, causing the front end — where the breathing part is located — to go underwater. Thus endeth the day’s lesson.

Evans Plunge has two major waterslides, one of which is called The Lazy River. The other waterslide plummets straight down from a nerve-racking height and should be called The Terrifying Tube of Watery Doom.

I went down both waterslides and each time I got dunked in a most undignified manner. Our grandson thought it was all great good fun.

We later drove through Custer State Park and chose to take the Wildlife Loop Road in the hopes of viewing some, well, wildlife. Sadly, all we saw were a few scattered bison off in the far distance.

After motoring some ways, we opted to turn back and soon found ourselves amid a herd of a hundred or more bison. The monarchs of the plains were casually lumbering across the road as if they owned it. Which they did.

There were massive, shaggy old bulls, and cows with brown calves trailing at their sides. One cow strolled past our car literally at arm’s length. My wife wisely heeded the admonition to never pet the fuzzy cows.

When we later talked to our grandson, he implied that one of the bison looked like me. I made a mental note to trim my beard.

The next day we drove to Iron Creek Lake, a pristine pond located in the wilderness of the Black Hills. The gravel road to the lake is twisty and jagged with sheer dropoffs and no guard rails. Speeders are thinned out via a Darwinian process.

Our son’s college buddy, Minnesota Jake (we’re not sure if that’s his real name), and his family have a trailer-type cabin at Iron Creek Lake. The sky-blue waters of the lake shimmered beneath the July sun as kayakers and paddleboarders glided lazily past the cabin. Shrieks of laughter echoed from the swimming beach located on the lake’s opposite shore.

Jake’s three kids are feral in the best sense of the word. They’re tanned and lithe and often run around barefoot. Jake’s 10-year-old son took our grandson on a frog hunting expedition at Frog Island, which is actually just a marshy area on the west end of the lake. Seeing the boys stroll away with landing nets over their shoulders was a Tom Sawyer moment.

There was no internet or cell service at the cabin, so our phones were reduced to paperweights. Which was how I found myself watching two boys who were watching a marsh for frogs.

— Jerry’s book, “Dear County Agent Guy,” can be found at www.workman.com and in bookstores nationwide.