A summer vacation to the United States national parks has been a rite of passage for generations of Americans—a pilgrimage made each season ever since the country’s best idea became reality over a century ago. Each summer, millions travel in search of the unique blend of natural awe and national pride that our most treasured landscapes inspire. Yet these warm-season sightseers are missing what might be the parks’ best-kept secret: winter.

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While Wyoming’s Yellowstone National Park is typically jam-packed from June through August, visiting during the winter allows tourists to experience the same striking scenery and abundant wildlife with far smaller crowds. From December to March, an Old Faithful eruption seldom attracts more than 15 onlookers, says Park Spokeswoman Sandy Snell-Dobert, compared to hundreds who gather every hour all summer long. And Yellowstone’s geysers, steam vents, and hot springs are especially spectacular in the frigid winter air, billowing steam up to 1,000 feet high and frosting the surroundings like a scene from Frozen. “You get these completely white-coated trees,” Snell-Dobert says. “It looks like Christmas gone wild.”

Freezing temperatures yield a fresh take on other familiar—and relatively unfamiliar—park landscapes, from ice-coated coastal cliffs in Maine’s Acadia National Park to the snow-covered forests of Sequoia & Kings Canyon in California. For parks with hotter climates, winter is actually high season: it’s by far the most pleasant time to enjoy the sawgrass marshes of the Florida Everglades and the desert scenes of Arizona’s Saguaro National Park.

Many of the National Park Service’s winter activities are in full swing by mid-December, with plenty of opportunities to hike, ski, or snowshoe through all the landscapes the parks have to offer. Don’t wait until summertime to join the fun: get started exploring these winter wonders now.

Everglades National Park in Florida

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From December through March, the subtropical dry season spells sunny skies, 70-degree days, and a break from the blood-sucking bugs that plague South Florida’s wetlands throughout the rest of the year. Less rain also concentrates wildlife at watering holes, boosting your odds of spotting the Everglades’ iconic alligators and wading birds like the bright pink roseate spoonbill.

Bryce Canyon National Park in Utah

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This southern Utah park’s gravity-defying limestone spires—called hoodoos—appear even more delicate when snow dusts the reddish-orange rocks. Join a ranger-led full moon snowshoe hike (November through March, snowpack permitting), or time your visit during a new moon phase for world-class stargazing beneath some of the West’s darkest skies.

Yellowstone National Park in Wyoming, Montana, and Idaho

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Winter ups the ante of the bizarre and beautiful landscapes of Yellowstone—counted among America’s best winter drives—as scalding geothermal features collide with single-digit winter air. Stay at the rustic Old Faithful Snow Lodge, open December through March and accessible only by snowcoach, to spot steam-frosted bison, glimpse frozen waterfalls, and watch the world’s most famous geyser with barely a soul in sight.

Acadia National Park in Maine

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Five feet of snow blanket Acadia’s evergreen forests and rocky headlands in an average year, transforming the park’s scenic loop drive and winding carriage roads into a paradise for cross-country skiers and snowshoers. Among Acadia’s little-known facts: in the winter months, ambitious early-risers can climb Cadillac Mountain to be the first in the country to catch the sunrise. Celebrate the season at the Acadia Winter Festival (Feb. 7 to Feb. 9), where naturalists of all ages can participate in winter ecology hikes, bird house building, dutch oven cooking, and more.

Saguaro National Park in Arizona

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Daytime temperatures average a comfortable 65 degrees from November through March at this gem just north of the Mexican border. Learn about desert-dwelling critters on a ranger-led nature walk, savor a smoldering Sonoran sunset, or simply marvel at the park’s namesake cacti, which can grow to be more than 45 feet tall and age over 200 years.

Black Canyon of the Gunnison National Park in Colorado

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Snowfall adds another dimension to the vertigo-inducing depths of this remote, rocky chasm in west-central Colorado. From December through April, ski or snowshoe the six-mile South Rim Drive to peer from clifftops to the Gunnison River nearly 3,000 feet below.

Sequoia & Kings Canyon National Parks in California

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