On August 25, the National Park Service (NPS) celebrates its 100th birthday. There have been many celebrations surrounding national parks in magazines (including EO) and across the Internet, which is important, especially considering the current, distressing war on the idea of public lands being waged by some extremist politicians. And while trumpeting the parks themselves is critical, it somewhat leaves out the most important part of this story. This should also be a celebration of the people who protect and manage the parks—the rangers and even administrators who make up the NPS, the service itself.

The idea of a national park hatched long before 1916, when President Woodrow Wilson signed the bill that created the NPS as part of the Department of Interior. The planet’s first national park was Yellowstone, carved out of the American frontier in 1872 when it was still raw. Soon, this revolutionary idea resonated with the people of the U.S. and the world. The painter George Catlin, considered one of the germinators of the concept exclaimed: “What a beautiful and thrilling specimen for America to preserve and hold up to the view of her refined citizens and the world in future ages! A Nation’s Park, containing man and beast, in all the wild and freshness of their nature’s beauty!” After thousands of years of reshaping nature, humans had decided it had a right to remain as it is, and maybe even that they need it that way.

The only problem was that keeping everything from poachers to wildfires managed and at bay in these protected landscapes, which by 1906 included national monuments, was a difficult task. The creation of the NPS sought to give the parks and monuments guardians on the ground. The task of those managers and rangers has since evolved. While they enforce park rules and federal laws in the wilds and in the often too crowded frontcountry, they are also educators. The best way to protect is to teach visitors the deep ecological and human history of these places, to light a fire in them that makes them also become guardians of what little is left of the once boundless American wilderness.

The national park system has evolved, too. It is more than simply wild places. It now includes urban recreation areas and historical sites like the Charles Young Buffalo Soldiers National Monument and the Caesar E. Chavez National Monument and Rosie the Riveter/World War II Home Front National Historical Park in California. Ninety-four-year-old Betty Reid Soskin, the oldest ranger to work for the NPS, still speaks to visitors at the latter. Other rangers like Shelton Johnson teach about some of the first park rangers, those buffalo soldiers, black army regiments sent to protect the parks after the Civil War.

Beyond these deep contributions, there are also the everyday NPS employees who hand out maps and clean bathrooms. There is the ranger who climbed down into a kiva with me and my kids at Mesa Verde National Park to better tell us the story of the people who once lived there. There are the patient law enforcement officers. There are even those faceless administrators who do the dull, dirty work of keeping these parks operating. Let’s celebrate them all this month. Thank them when you visit your next site in the national park system. They are why it’s still here, and growing.