They walk among us. Shuffling along sidewalks, mesmerized by the smartphones cradled in their hands. Some have earbuds in, seemingly oblivious to the physical world around them.

They are Pokémon Go players, and they are on one mission: They’ve gotta catch ‘em all.

From teenage girls to police officers, it seems like everyone is hopping on the augmented reality bandwagon to hunt down their first Charmanders, Squirtles, and Bulbasaurs. Recently ranked as the most popular game in U.S. history, the phenomenon has made its way through civilization and is now venturing into uncharted territory: national parks.

Searching Far and Wide

“There’s always a push-pull between how we experience our parks virtually and how we experience our parks in real time,” says Tim Rains, a public affairs specialist at Glacier National Park. “Here is this combination of the two.”

With lush trees and mountain ranges, national parks are not the easiest places to find cell reception or Wi-Fi. Because of this, Barb Maynes, public information officer at Olympic National Park, says she hasn’t heard reports of people playing Pokémon Go. Acadia National Park also hasn’t reported any activity.

But some visitors centers, which have Wi-Fi, double as pokégyms, or places where players can battle each other and level up. On Tuesday, Rains caught his first Pokémon—a Bulbasaur—near Glacier’s Apgar Visitor Center.

Lynda Doucette, a lead interpretive ranger at Great Smoky Mountains National Park, says the park’s landscape obstructs cell service. But she and her colleagues have found at least five Pokéstops, landmarks where players can collect useful items, and a Pokégym. They’ve identified at least 12 Pokémon, including Zubats and Squirtles.

“One of our goals as part of the National Park Service Centennial is to connect with and create the next generation of park visitors, supporters, and advocates,” Rains writes in an email. “Games that use geolocation are a new and emerging opportunity to bring new audiences to the park.”

Pokémon Go also has an educational component to it. Great Smoky Mountains’s Mountain Farm Museum has three Pokéstops. When found, historical text will pop up on screen, and players can tap an icon to learn more before returning to the game. There’s also a Twitter account called Pokémon Archaeology devoted to recording Pokémon in historical settings.

“It gets people out there,” Doucette says. “I think it’s an opportunity to bring a new audience to a site.”

Pokémon are popping up in Yosemite National Park, too. Spencer Gediman, the 12-year-old son of the park's public affairs officer Scott Gediman, spent nearly five hours playing Pokémon Go around Yosemite Village on Thursday. He came across about 40 creatures, mostly Pidgey, Nidoran, and Clefairy. He even found a Raticate in his father’s office.

Spencer ran into other players throughout the day. He saw lots of families playing together around places like the church, post office, and village store, which are Pokégyms.

“This game is really big,” Spencer says. “It’s all friendly. It’s really awesome.”

Potential Pitfalls

But as play increases, injuries abound. Already, players have been hurt after falling or walking into obstacles while cruising for critters. So far, though, national parks aren’t implementing any policies against the game.

Instead, Emily Davis, a public affairs officer at Grand Canyon National Park, says rangers will continue to remind visitors to be aware of their surroundings on their quests to track down new Pokémon.

“I don’t anticipate that we’re going to have any new rules implemented,” Doucette says. “It’s the same safety concerns we’ve had before this game.”

Overall, Pokémon Go may become a new way to explore historic parks, which tend to be dead spots for technology. In Washington, D.C., rangers will even soon be getting in on the game by leading a “Catch the Mall Pokémon Hunt,” according to the National Mall and Memorial Parks Facebook page.

“On top of reminding visitors to be safe during their visit, we are also asking them to be respectful of the solemn monuments and to avoid wandering into off-limits areas,” Tom Crosson, chief of public affairs for the National Park Service, writes in an email.

Who knows? Maybe Pikachu could end up on Mount Rushmore one day.