(This article by Louisiana-based writer Kathie Rowell originally appeared in the June 2024 issue of Military Officer, a magazine available to all MOAA Premium and Life members. Learn more about the magazine here; learn more about joining MOAA here.)

From Acadia to Haleakala and Denali to the Everglades, the U.S. has some of the most spectacular and diverse public lands on the planet.

The more than 325 million visitors who flocked to the 63 national parks and 366 national landmarks, monuments, seashores, and historic sites overseen by the National Park Service in 2023 attest to their popularity. Each park unit — from the most-visited attraction at more than 16.7 million for the Blue Ridge Parkway through Virginia and North Carolina to one of the least visited at 200 for Aniakchak National Monument and Preserve in Alaska — has its own appeal.

The thousands of state parks across the country offer even more opportunities to enjoy recreation and history.

Lt. Col. Thomas Osterhoudt, USMC (Ret), feels the attraction. He and wife, Karen, have spent the past 13 years on a quest to visit all 429 national parks and landmarks. So far, they’ve crossed 304 off the list. They’ve also visited 25 of the 42 state parks in Virginia, where they live.

The Osterhoudts began their adventure as he approached active duty retirement in 2012.

“I spent the last 27 years defending the nation. Do I really know what I was defending? I wanted to explore the nation,” he said.

The Osterhoudts are members of the National Park Travelers Club (NPTC), which offers trip-planning resources, progress certificates, and community forums.

Craig Bailey, NPTC secretary, said there are 96 members known to have visited all the parks.

“I don’t know about others’ fascination with national parks, but for me, I just love traveling. And I love our national parks. I love history, beautiful scenery, and seeing it all.”

Click the links below to learn about some of the country’s great national and state parks.