1. Mark O. Hatfield Wilderness, Oregon

Just south of the Columbia River Gorge, Mark O. Hatfield Wilderness was expanded in 2009 to include the spectacularly lush cliffs, canyons and waterfalls of Gorge Face. With breathtaking panoramic views of the Cascade Range, its forests, meadows and subalpine lakes offer a popular destination for nearby Portland residents. Visitors can embark upon a range of delightful adventures, including fishing, horseback riding, camping, rafting, backpacking and wildlife watching. Among the 200 miles of trails, hikers can enjoy a jaunt on the regional Pacific Crest Trail.

photo: Oneonta Gorge. credit: Michael Matti, flickr.

2. Marjory Stoneman Douglas Wilderness, Florida

This place is a wildlife paradise, offering opportunities to see almost every organism that lives in the Caribbean. The marsh water is filled with fish, bottle-nosed dolphins, sea turtles, sharks, manatees and alligators. Hundreds of colorful birds nest here as well - flamingos, roseate spoonbills, egrets, herons, pelicans, cranes, hawks, ibis, storks, frigate birds, kites and skimmers. Boaters can access Florida Bay and the remarkable Wilderness Waterway, a 99-mile marine trail that journeys through Everglades City, Ten Thousand Islands and Flamingo. The Marjory Stoneman Douglas Wilderness lies inside Everglades National Park, and is named for the woman who was a strong advocate for the protection of the national park.

photo: Everglades National Park. credit: Joe Parks, flickr.

3. Carlsbad Caverns Wilderness, New Mexico

Spelunkers would be hard pressed to find a better place to explore than Carlsbad Caverns. Its 118 caves include the world-famous Carlsbad Cavern and 125-mile long Lechuguilla Cave. Over 120 miles have been mapped to a depth of 1,600 feet, making it the deepest limestone cave in the nation. Its largest chamber is also the fifth largest on the continent. No surprise that it is a haven for bat lovers too - 17 different species live here.

photo: Carlsbad Caverns. credit: Marcus Calderon, flickr.

4. Joshua Tree Wilderness, California

Joshua Tree's fascinating rock formations and colorful monoliths draw climbers from around the world. Tis Wilderness area represents the convergence of two major desert ecosystems - the lower, drier Colorado Desert and the cooler, wetter Mojave Desert, where the Joshua tree grows. There are also five fan-palm oases here, which come to life at night with tarantulas, rattlesnakes, coyotes, jackrabbits, bobcats, kangaroo rats and burrowing owls. At night this Wilderness also becomes an ideal stargazing location.

photo: Joshua Tree National Park. credit: The City Project, flickr.

5. Boundary Waters Canoe Area Wilderness, Minnesota

Boundary Waters is one of the most visited of all U.S. Wildernesses and for good reason. With 1,200 miles of canoe routes, 18 hiking trails and nearly 2,200 campsites, there’s plenty of adventure as well as solitude to be found. In the winter, visitors enjoy skiing, dog-sledding and ice-fishing as well. Stargazers may also spy the northern lights during the equinoxes. Unfortunately, there have been recent attempts to mine copper in sulfide-bearing ore nearby, which could contaminate Boundary Waters' lakes and rivers, harming fish and wildlife.

photo: Boundary Waters Canoe Area Wilderness. credit: Adam Baker, flickr.

6. Rocky Mountain National Park Wilderness, Colorado

The Rocky Mountain National Park Wilderness was designated in 2009. It contains more than 350 miles of trails for hikers, backpackers and horseback riders to savor all year long. Snowshoers and cross-country skiers find tranquil meadows and forests in the winter months. Spring ushers in wildflowers and birds, delighting photographers from across the world. Of its more than sixty peaks over 12,000 feet high, Longs Peak is the highest and most popular in summer. Autumn’s stunning golden aspens are accompanied by bugling elks.

photo: Rocky Mountain National Park. Credit: Alex Berger, flickr.

7. Zion Wilderness, Utah

Zion National Park is a geological masterpiece with high plateaus, towering cliffs and a labyrinth of sandstone canyons. Massive rock is shaped by the rare desert waters of the Virgin River, which carves a green ribbon of diverse plants and animals through the canyon oasis. For hikers, it’s a natural sanctuary - indicated by its name, a Hebrew word for refuge. The heat can be unbearable in summer, so you might want to visit in fall.

photo: View from Angels Landing in Zion National Park. credit: fortherock, flickr.

8. Death Valley Wilderness, California

As one of the continent’s hottest and driest locations, Death Valley is surprisingly also an International Biosphere Reserve. Expansive fields of desert sand dunes and unique rock formations create stunning landscapes. In spring, these spaces are sprinkled with colorful wildflowers. Death Valley is also an International Dark Sky Park, perfect for gazing at faraway galaxies. This area occupies 95% of the country’s largest national park in the lower 48 states.

photo: Death Valley National Park at night. credit: David Kingham, flickr.

9. Paria Canyon-Vermilion Cliffs Wilderness, Arizona

This one-of-a-kind landscape is considered one of the world’s best canyon backpacking destinations. Narrow, serpentine slot canyons make Paria Canyon-Vermillion Cliffs an incredibly photographic landscape. “The Wave” is the most famous for its picturesque forms, but it’s only one of many breathtaking sculpted walls streaked with desert colors. Visitors can also spy red rock amphitheaters, sandstone arches as well as hanging orchids.

photo: The Wave in Paria Canyon-Vermilion Cliffs Wilderness. credit: James Gordon, flickr.

10. Hawaii Volcanoes Wilderness, Hawaii

Hawaii Volcanoes National Park has 150 miles of trails, most of which journey through its designated Wilderness areas. The Ka'u Desert Trail, for example, winds past lava fields and cinder cones in the park's southwestern section, which also includes several miles of coastline. The northwest area of the park includes the summit of the volcano Mauna Loa, while the protected Olaʻa Forest is north of the park. This wilderness area is another that boasts magnificently dark skies.

photo: Kīlauea Iki Crater in Hawaii Volcanoes National Park. credit: ArtBrom, flickr.

11. Sequoia-Kings Canyon Wilderness, California

This Wilderness area is replete with just about everything a nature lover could ask for: high peaks, deep canyons, rich meadows, serene lakes, wild rivers and, of course, enormous trees. It is crossed by two well-loved trails as well - 101 miles of the Pacific Crest Trail and 97 miles of the John Muir Trail.

photo: Sequoia National Park. credit: Tobias, flickr.

12. Yosemite Wilderness, California

Yosemite's features have a timeless beauty, including El Capitan, Half Dome, Yosemite Falls, Bridalveil Fall and Tuolumne Meadows. Green forests, blue lakes and clear streams become white with frost in winter. Iconic vistas, distinct bird populations and world-class rock-climbing opportunities attract millions to this gem in the heart of the Sierra Nevada each year. Moonbows present a rare treat to those visiting here as well. With a 150-year history of protection, Yosemite remains one of America’s most beloved national parks.

photo: Yosemite National Park. credit: Trey Ratcliff, flickr.

13. Olympic Wilderness, Washington

Washington's largest wilderness area has 48 miles of beautiful Pacific Ocean coastline. But beaches are only a fraction of what is protected here. Temperate rainforests filled with old-growth trees provide habitat to abundant wildlife, and mountains provide challenging adventures and stunning vistas for visitors. The highest peak, Mount Olympus, has the third largest glacier system in the continental U.S. This wilderness represents 95% of Olympic National Park.

photo: Olympic National Park. credit: Michael Renfrow, flickr.

14. Bisti/De-Na-Zin Wilderness, New Mexico

The Bisti Badlands have a truly distinct landscape. Strange rock formations of sandstone, shale, mudstone, coal and silt form mazes and hoodoos in an otherwise stark desert. This is the place where researchers think dinosaurs passed into extinction - a fact that adds to its eerie quality. It remains nearly lifeless today, making it one of the most quiet destinations imaginable.

photo: Bisti/De-Na-Zin Wilderness. credit: BLM New Mexico, flickr.

15. Frank Church - River of No Return Wilderness, Idaho

One of the things that makes Frank Church - River of No Return so remarkable is its sheer magnitude. As the second largest in the continental U.S., this wilderness is known best for - you guessed it - clear, white-water rivers. The Main Salmon River carves a canyon deeper than the Grand Canyon, and its Middle Fork is a legendary rafting destination. The surrounding rugged mountains are home to a wide variety of species, including mountain lions, gray wolves, black bears, moose and rare wolverines.

photo: Middle Fork of the Salmon River. credit: Northwest Rafting Company, flickr.

16. Sawtooth Wilderness, Idaho

You can breathe in some of the cleanest air in the lower 48 at Sawtooth. Hundreds of high granite peaks are sprinkled with hundreds of alpine lakes. Deep valleys are filled with large trees and the fish-filled headwaters of several major rivers. Although the hiking season is short, there are 350 miles of trails to explore. Wildflowers peak in July and August but beautiful scenery lasts all year. Horseback riding and camping are popular ways to experience this wild heaven.

photo: Redfish Lake in Sawtooth Wilderness. credit: Monika Clarke, flickr.

17. Maroon Bells-Snowmass Wilderness, Colorado

Maroon Bells-Snowmass is exemplary of all that the Rocky Mountains are known for and is one of the area's most visited wildernesses. With six peaks over 14,000 feet high, thousands of mountaineers seek its heights every year. One hundred miles of trail lead past alpine lakes, including Maroon Lake whose reflection of the Maroon Bells has become the iconic image of the state. Hikers are drawn to its clear, blue skies, the hot springs at Conundrum Creek and a plethora of wildflowers in midsummer. The area was designated when the Wilderness Act passed fifty years ago, in 1964.

photo: The peaks known as the Maroon Bells. credit: Chad Weisser, flickr.

18. Teton Wilderness, Wyoming

Teton Wilderness lies in the sweet spot between Yellowstone and Grand Teton National Parks. Straddling the Continental Divide, Teton hosts the famous Two Ocean Creek, which sends water to the Atlantic and Pacific, as well as the boat-worthy headwaters of the Snake River. This is one of America’s best areas to view wildlife - including trumpeter swans, sandhill cranes, grizzly bears, grey wolves, moose, golden and bald eagles, porcupines and otters - so many visitors enjoy hunting and fishing here. With its exquisite colors, fall may be the best time to visit.

photo: The Tetons. credit: Trey Ratcliff, flickr.

19. Pemigewasset Wilderness, New Hampshire

The "Pemi" is the largest wilderness area in New Hampshire’s legendary White Mountain National Forest - and area known for hosting the nation’s greatest network of hiking trails, including the popular Wilderness Trail and the magical Appalachian Trail. This area is considered one of New England’s best backpacking destinations. It is also one of the most extensive roadless areas in the eastern U.S., offering unblighted, sweeping panoramic views for visitors. Its hardwood forests are inhabited by moose, bears, coyotes and foxes.

photo: Pemigewasset Wilderness. credit: Reid Gilman, flickr.

20. Mollie Beattie Wilderness, Alaska

Stretching down Alaska's Brooks Range are prime habitats for numerous Arctic animals: brown and black bears, moose, wolves, musk oxen, arctic foxes, polar bears, and caribou. Whales and seals migrate through Arctic seas and birds traveling from as far away as Antarctica fly overhead. There is no place in America that is as pristine as the beloved Arctic National Wildlife Refuge, which this Wilderness occupies 40% of. It was named after the first female director of the U.S. Fish and Wildlife Service.

photo: Arctic National Wildlife Refuge. credit: Lincoln Else.