Help ring in a centennial of the National Parks Service by hitting the trail for the best hikes in each of Colorado’s four national parks.

On August 25, the National Park Service turns 100. We can’t think of a better way to celebrate one of our country’s best ideas and ring in a second century of stewardship than to get out and explore one—or all—of Colorado’s four national parks. Read on to find out about our favorite adventures; then start planning your own journey

HIGH

Rocky Mountain

The Big Loop

Over three million visitors  a year flock to this high-altitude gem, making it sometimes hard to find solitude. We’ve got just the antidote: a 25-mile backpacking loop that starts on the less visited and wetter west side, tops out on the Continental Divide and gives a taste of all that Rocky Mountain has to offer, including opulent wildflower displays, opportunities to see wildlife such as moose and elk, and breathtaking views. Allow three days to savor this adventure, which begins at the Tonahutu/North Inlet trailhead near Grand Lake. Walk through lush forest alongside rushing water as you ascend through the quieter side of the park via the North Inlet Trail. Stop at Cascade and War Dance falls before reaching the Lake Nanita Trail junction. If time and energy allows, the 6-mile roundtrip to Nokoni and Nanita lakes is worth the effort.  Enjoy big vistas as you continue climbing via the North Inlet Trail, which follows Hallett Creek to reach the blossom-adorned tundra of the Continental Divide and tops out on Flattop Mountain (12,324 feet). Turn northwest on the Tonahutu Trail, cross Ptarmigan Pass and descend through Bighorn Flats to reach a junction with the Haynach Lake Trail (another worthy optional side trip with excellent campsites). From here, enjoy a well-earned downhill tromp via the Tonahutu Trail, which passes Granite Falls, Lower Granite Falls and Big Meadows, before you finally reach the trailhead. nps.gov/romo

ANCIENT

Mesa Verde

Wetherill Mesa

Step back in time with a visit to southwestern Colorado’s Mesa Verde, where 5,000 known archeological sites, including 600 cliff dwellings, offer a glimpse into the lives of the Ancestral Pueblo people who lived here for over 700 years. Most visitors focus on the famed Cliff Palace (which is indeed impressive), so a visit to Wetherill offers a more tranquil Mesa Verde experience. Plus, because park officials created this oft-overlooked spot with walking and bicycling in mind, you are free to discover most of the sites on your own via self-guided trails. Follow a winding, one-mile path to tour the pithouse, petroglyphs and cliff dwelling of the Step House. Then take the 2.25-mile Badger House Trail to discover four mesa top sites. Take advantage of the knowledgeable staff, too, and don’t miss the ranger-guided tour of the park’s second largest ancestral cliff dwelling, the Long House, which includes climbing two 15-foot ladders. nps.gov/meve

EMPTY

Great Sand Dunes

Star Dune

Most Americans think big peaks, raging rivers and high alpine lakes, rather than a giant expanse of sand dunes, when they picture the the Centennial State. However, Great Sand Dunes National Park and Preserve is home to the tallest dunes in North America. Exploring this magical place on foot affords the experience of a lifetime: You’ll hoof it over an ever-changing alien landscape where sand, forest and the snow-capped Sangre de Cristo Mountains collide. The dunes proper have no trails, so you can truly explore by following Mendano Creek or the undulating ridges of shifting sand. Or travel a little further afield than most by tromping past High Dune, part of the most prominent first ridge, to climb Star Dune, which rises 755 feet from its base to crest. To reach it typically requires a five-hour round trip adventure. Take advantage of the park’s unmatched stargazing by spending the night. You can camp anywhere along the dunes (free permits are available at the Visitor Center).  nps.gov/grsa

DEEP

Black Canyon of the Gunnison

North Vista Trail

Wind, water and time have carved the narrow canyon at the center of this remote and rugged park characterized by its sheer cliffs, craggy spires and ancient rock. Dark rock walls drop over 2,000 vertical feet to reach the Gunnison River, but there are no established trails that will bring you to the canyon bottom, only steep and slippery rock gullies that intrepid anglers—drawn to the gold-medal trout waters of the Gunnison—occasionally use for scrambling. The trip back up is painful, however, so we suggest you explore the canyon from above on our favorite hike here, the seven-mile-round-trip North Vista Trail, which starts at the ranger station on the lesser-visited north rim and follows the canyon’s edge through sagebrush and pinyon-juniper forest. Views of SOB draw and the inner canyon spread out before you as you head toward the aptly named Exclamation Point. Continue to Green Mountain (867 feet higher) for panoramic views of the San Juans, West Elks, Grand Mesa and an even cooler perspective of Black Canyon that includes both the rim and the inner canyon. nps.gov/blca