For 50 years I have been an avid fan of America’s national parks. I’ve gone on state-spanning camping trips since the early 1960s, but it wasn’t until I visited Yellowstone and Grand Teton in Wyoming that I realized how magnificent and unusual America’s topographical features are.

The shooting geysers, boiling turquoise pools and thunderous waterfalls echoing through the Grand Canyon of the Yellowstone made me feel like my eyes had opened for the first time. It felt otherworldly to see deep snowpack in June and to travel above the clouds while still remaining on the ground.

It wasn’t until the 1990s that my wife and kids joined me on my decades-long odyssey through more than 30 national parks. Yellowstone and Grand Teton were the first parks that my sons visited, just as they were my first when I was their age. My sons took away similar life lessons that I did. Our national parks provide the ultimate firsthand learning experience for geography, geology, botany, zoology, hydrology and even meteorology.

Of all the parks I’ve visited, I would have to say that Yosemite is my favorite — it greets you with the roaring Merced River as it opens up its valley floor, whose aura feels lifted straight out of Tolkien’s Rivendell. Yosemite’s cliff-spanning waterfalls and granite features such as El Capitan, Sentinel Dome and Half Dome firmly establish the park as one of the world’s geographic wonders.

High above the valley are passes filled with the snow-capped Sierra Nevada Mountains, alpine lakes and flowered meadows; adding to the spectacle are vast sequoia groves and clear streams framed by sheer cliffs, a staggering topography with breathtaking views around every corner.

One of the personal highlights of my Yosemite experience was my trek along the John Muir Trail, named after the famed naturalist who helped preserve Yosemite Valley and Sequoia National Park in the early 1900s. The trail, which extends more than 200 miles from Yosemite to Mount Whitney (the highest peak in the 48 contiguous states), can be traversed by a moderately strenuous climb to Vernal Falls and Nevada Falls.

These are just two of the 19 waterfalls in the park that plunge more than 300 feet, and their torrent of snowmelt is thunderous enough to drown out even the shouts of the person standing next to you.

The key to enjoying Yosemite and any of the other popular national parks to their fullest is to go during shoulder season (late spring or late fall) in order to avoid the crush of tourists. Yosemite’s best showing is in April and May, when its waterfalls are most active.

For me, Yosemite is definitely the gem of gems, but all of our nation’s parks are precious.

All 59 national parks are remarkable in countless ways, and each is unique as well as fragile. We are but guests in these places, and we should treat them with respect — those who don’t tend to underestimate nature’s unpredictable weather and challenging topography while overestimating their own ability to conquer them. As a result, about 150 tourists lose their lives in national parks every year. The vast majority of park visitors, of course, realize their own insignificance in the grand scheme of nature, and for that they take their incredible experiences with them to share and keep for the rest of their lives.

This summer, my wife and I will celebrate the 100th anniversary of the National Park Service by returning together to Yellowstone, Grand Teton and Glacier, where our odyssey through nature began. And this fall, we will reflect on our 30 years of marriage as we renew our vows on the south rim of the Grand Canyon.

But now, as I reflect on my many trips, I realize that our national parks are more than American treasures: They are the world’s educational, spiritual and natural playgrounds that flood all of our senses, and our decision to safeguard them for future generations was truly America’s greatest idea. 

Tony Koelsch of Champlin describes himself as “a lifelong fan of our national parks.”