Even during the ongoing coronavirus crisis, many of America's national parks are preparing to welcome summer visitors.
The iconic Yosemite, for example, will require advanced reservations for day visitors during the peak summer season. The goal is to limit the number of visitors, and allow social distancing in the nearly 1,200-square-mile federal preserve. Other national parks, such as Glacier in Montana, also have begun to dole out advance tickets.
Thinking of booking a trip? Here's a ranking of every national park in the United States, determined by the number of 2020 visitors.
62: Gates of the Arctic National Park
2020 visitors: 2,872
Located north of the Arctic Circle, Alaska's Gates of the Arctic is almost totally inaccessible to outsiders, has no roads going in or out, and has extensive restrictions on camping and hunting.
But if you do make the trip to America's second-largest national park, you'll be rewarded with panoramic views of glaciers, a hardy population of brown bears and some of the most beautiful rivers in America.
61: National Park of American Samoa
2020 visitors: 4,819
The only national park located south of the equator, the National Park of American Samoa is a refuge of tropical forests, coral reefs, beaches and hiking trails.
It has some of the largest living coral reefs in the world. Those reefs are under constant threat from climate change, and might disappear by the middle of the 21st century if carbon dioxide emissions aren't reduced.
60: Lake Clark National Park
2020 visitors: 4,948
Another hard-to-access northern Alaskan park, Lake Clark's biggest feature, literally, is its two active volcanoes, Mount Redoubt and Mount Iliamna.
Redoubt has erupted numerous times in the last century, including a 1989 blast that turned out to be the second most destructive eruption, in terms of dollar cost, in U.S. history. It threw up so much ash that it nearly downed an airliner flying nearby.
59: Glacier Bay National Park
2020 visitors: 5,748
Glacier Bay sees most of its traffic from cruise ship excursions.
Unlike many parks, it allows sport hunting for bears and other species.
58: Isle Royale National Park
2020 visitors: 6,493
Located just south of the Canadian border in Michigan, Isle Royale is actually about 400 islands of various sizes, and is almost entirely a wildlife preserve.
It has a small population of moose that live (mostly) in harmony with an even smaller population of wolves, a relationship that has inspired 50 years of scientific study.
It has just a few campgrounds, and is the only national park that closes entirely for the winter, since bad weather makes it unreachable.
57: Kobuk Valley National Park
2020 visitors: 11,185
Like its Alaskan neighbor Gates of the Arctic, Kobuk Valley is difficult to reach, with limited flights and no road access in or out.
It's mostly designed as a wildlife preserve, with tourism taking a backseat to protecting the sand dunes — some of the biggest in North America. Those Arctic dunes are so precious that NASA has studied them as a model for what secrets dunes on Mars might reveal.
56: Wrangell-St. Elias National Park
2020 visitors: 16,655
About two-thirds of this gigantic Alaskan park is a 9-million-acre sprawl of wilderness — the biggest of its kind in America. But the accessible parts of the park also include an abandoned mining town only reachable by airplane or a five-mile drive on a gravel road.
The park also has abundant fishing and birdwatching, kayaking, and challenging mountain climbs.
55: North Cascades National Park
2020 visitors: 30,885
Sprawling over three Washington counties, North Cascades consists largely of protected forest, glaciers, and mountain peaks. It has very limited accessibility, and it's prone to avalanches and heavy snows.
But with hundreds of lakes, spectacular old-growth forests, challenging climbs and some of the greatest biodiversity in the entire national park system, intrepid visitors will be rewarded for going the extra mile to visit.
54: Dry Tortugas National Park
2020 visitors: 48,543
Located 70 miles west of the Florida Keys, Dry Tortugas are a unique combination of undisturbed wildlife and historical artifacts, including an unfinished Civil War-era fort.
The park is 99% water, with limited access to the islands that make up the rest. One of its most famous fishermen was Ernest Hemingway, who was marooned there with his buddies by a storm surge for more than two weeks.
53: Katmai National Park
2020 visitors: 51,511
Most of the 4-million-acre Katmai National Park in Alaska is a designated wilderness and off limits to tourists.
The park has stunning biodiversity, including more than 2,000 brown bears — the largest protected population in the world. It also features nearly 20 volcanoes, at least seven of which are active.
Katmai made international headlines in 1989 when its pristine coastline was badly polluted by oil from the Exxon Valdez spill, a disaster that took decades to address.
52: Denali National Park
2020 visitors: 54,850
Central Alaska's Denali is home to the tallest mountain in North America, now called Denali, but previously known as Mount McKinley.
The controversy over the mountain's name started in earnest in the mid 1970s, and pitted Alaska (whose residents always called it Denali) against Ohio, the home of President William McKinley. President Barack Obama finally ended it with a 2015 executive order mandating the name change.
51: Kenai Fjords National Park
2020 visitors: 115,882
Kenai Fjords is another one of Alaska's parks, featuring a gigantic field of nearly 40 glaciers and extensive bear and whale populations. But unlike many other parks in the state, it's much easier to access.
It's also a major port for cruise ships, bringing in large numbers of tourists and hikers. Kenai suffered major damage because of the Exxon Valdez spill in 1989.
50: Congaree National Park
2020 visitors: 119,306
Located in central South Carolina, Congaree contains the largest remaining wilderness of old growth hardwood forest in the United States.
But Congaree is probably best known for its firefly populations, which spend two weeks every early summer performing synchronized light displays to attract mates.
49: Great Basin National Park
2020 visitors: 120,248
Great Basin, the largest desert in the United States, sprawls over eastern Nevada. It offers some of the oldest trees in the world, deep caves, and vast landscapes of sagebrush and desert animal habitat. Its highest point is almost a mile above its lowest point.
Located 200 miles from Salt Lake City and 300 miles from Las Vegas, the park is accessible but remote, and has extreme temperature variations, from scorching heat to brutal cold.
48: Guadalupe Mountains National Park
2020 visitors: 151,256
Guadalupe Peak is the highest point in Texas, and it's just one of the attractions in the park. It also features the world's biggest Permian fossil reef, and a long history intertwined with the struggle of Texas' native people.
The park is so big that it has everything from arid salt flats to alpine forests.
47: Pinnacles National Park
2020 visitors: 165,740
The famous rock formations that form the pinnacles are left over from an eroded volcano, and make up most of the sprawling central California park. There are few developed campgrounds, though the eastern and western parts of the park don't connect.
Still, Pinnacles has extensive and brisk hiking trails, as well as the most diverse population of bees anywhere on Earth. Up to 400 different species make their home there — encompassing everything from massive colonies to single, solitary queens building hives.
46: Channel Islands National Park
2020 visitors: 167,290
Despite being just off the coast of bustling Los Angeles, the Channel Islands are sparsely populated and mostly undeveloped.
The five biggest islands in the northern part of the chain comprise almost 250,000 acres of some of the richest marine ecosystems on the planet. There are dozens of species in the park that can't be found anywhere else on Earth, including unique foxes and birds.
45: Virgin Islands National Park
2020 visitors: 167,540
Virgin Islands National Park consists of a few small islands and more than 5,000 acres of open ocean. The park is best known for its diving and abundant sea life, beautiful beaches and well-preserved plantations and mills.
44: Carlsbad Caverns National Park
2020 visitors: 183,835
Part of the same range as Texas' Guadalupe Mountains, Carlsbad has nearly 120 caves total, including the legendary Big Room — one of the largest underground chambers in the world.
Carlsbad is also home to as many as 500,000 bats, which take to the sky in huge flights as night falls during the summer.
The Carlsbad cave complex is so big that new discoveries are constantly being made, including an ancient pool of milky blue water recently found 700 feet below ground in one of the smaller caves.
43: Voyageurs National Park
2020 visitors: 263,091
Located just south of the U.S.-Canada border in Minnesota, Voyageurs sits on exposed rock formations that are roughly 3 billion years old. The park's main entrances are all on the water, and it's popular with boaters, kayakers, and fishers.
In winter, its large lakes freeze over, and you can ski or snowshoe over them. The park also offers excellent views of the Northern Lights.
42: Redwood National Park
2020 visitors: 265,177
The sprawling Redwood National Park is actually made up of four smaller parks managed by both California and the National Park Service.
Redwood's trees are some of the tallest and oldest in the world, and are heavily protected from logging and camping. Its striking vistas are so otherworldly that one of its tree groves was used for filming the Forest Moon of Endor scenes in "Return of the Jedi." The park was also used as a location for "The Lost World: Jurassic Park" and "Outbreak."
41: Mesa Verde National Park
2020 visitors: 287,477
Mesa Verde was established to protect some of the most well-preserved Native American pueblos in all of North America, homes carved into the towering rock formations that date back to the 12th century.
More recently, the Colorado park has battled huge wildfires, which have burned as much as 70% of the park at different points — but have also revealed hundreds of previously unknown Native American structures.
40: Mammoth Cave National Park
2020 visitors: 290,392
Kentucky's Mammoth Cave is the largest cave system in the world, going on for more than 400 miles of twisting tunnels and dead ends.
It's also home to the tiny, blind, colorless Kentucky cave shrimp. The shrimp was thought to be extinct in the 1970s, a victim of the unchecked pollution of America's rivers. But several years after the Clean Water Act was passed in 1972, researchers started finding them again, and they're studied as an indicator of the overall health of the park's underground waterways.
39: Haleakalā National Park
2020 visitors: 319,147
Located on a dormant volcano on Maui, Haleakalā has more endangered species than any other national park, with more than 100 making their home there. Most of these are rare plants.
Massive flocks of feral pigs, goats and deer roam this part of Hawaii, routinely trampling the fragile soil and eating the endangered flora. Park officials have had to put extensive fencing up to keep the animals from doing further damage.
38: Black Canyon of the Gunnison National Park
2020 visitors: 341,620
The "black" in Black Canyon isn't about the rock or wildlife in this western Colorado park, but darkness — some of the deepest parts of the gorge that make up the park get virtually no sunlight.
But the canyon itself is accessible via hiking, and the park can easily be driven through. The Gunnison River that runs through the canyon is a boon for experienced fishers and kayakers, and the rest of the park offers great birdwatching.
37: Petrified Forest National Park
2020 visitors: 384,483
While other parks struggle with the effects of human-caused climate change, Petrified Forest National Park in Arizona has a different problem — theft. So much fossilized wood has been stolen from the park that it led to an urban legend: Those who stole pieces were cursed to bad luck.
The park routinely gets apologetic letters from people returning a piece of wood they or a family member stole; it got nearly 100 when the curse was mentioned on an episode of the Netflix series "Dead to Me."
36: Big Bend National Park
2020 visitors: 393,907
South Texas' Big Bend National Park is not only a protected wilderness, but also an active border crossing between the U.S. and Mexico. The Rio Grande runs through more than 100 miles of the park, and crossing the border requires a trip via rowboat.
Big Bend also offers spectacular views and diverse ecology — especially at night.
35: Biscayne National Park
2020 visitors: 402,770
Located south of Miami, Biscayne National Park is almost entirely water, with the only land being a mix of coral and sand islands.
During the Cold War, the area's biggest island was used as a training ground for Cuban exiles preparing for the botched Bay of Pigs invasion. More recently, the park has grown popular for fishing, diving and glass-bottomed boat tours.
It's particularly well known as a manatee sanctuary, as the giant mammals head south during the winter for warmer water.
34: Kings Canyon National Park
2020 visitors: 415,077
Kings Canyon in California was once one of the most popular parks in America, averaging more than a million visitors per year well into the 1970s. But much of its land was closed off to tourists and declared a protected wilderness in the 1980s.
Part of that wilderness includes the famous General Grant sequoia tree. It's the second-tallest tree in the world and known as "America's Christmas Tree," despite it being too tall and fragile to actually decorate.
33: White Sands National Park
2020 visitors: 415,383
Already a national monument for decades, White Sands in New Mexico is America's newest national park, designated in December 2019. Before that, it was a major location for movie filming, and it's still heavily visited for sledding, sand skiing and nature walks.
The park is also surrounded by White Sands Missile Range, meaning you might see strange-looking planes or rockets buzzing around. When the missile range fires off a test, the park closes, so check their website before you plan your visit.
32: Wind Cave National Park
2020 visitors: 448,405
This South Dakota park features the densest cave system in the world, one of the longest individual caves in the world, and the last remaining natural grass prairie in North America.
In 2019, Wind Cave got an unexpected media hit: It came up during a Democratic presidential debate spat between former South Bend Mayor Pete Buttigieg and Minnesota Senator Amy Klobuchar, who ridiculed Buttigieg's hosting a fundraiser in a wine cave, saying "I have never even been to a wine cave. I've been to the Wind Cave in South Dakota, which I suggest you go to."
31: Great Sand Dunes National Park
2020 visitors: 461,532
The dunes that make up this park in southern Colorado are the tallest in North America and stretch on for hundreds of miles. They have fossil beds; appear to move on their own thanks to the wind; and even "sing" when air is pushed through the millions of grains during avalanches.
Despite being fragile, the dunes are available for hiking, sand surfing and sand skiing. But be careful — the surface of the sand can reach 150 degrees Fahrenheit during summer and plunge to minus-20 on winter nights.
30: Gateway Arch National Park
2020 visitors: 486,021
For most of its life, the area encompassing St. Louis' famous metal arch was a park called the Jefferson National Expansion Memorial. Built to commemorate the famed Lewis and Clark expedition, it was renamed in 2018 and officially designated as a national park to help protect and expand the grounds.
Like virtually every other human-created monument in the country, the Arch was closed for months due to COVID-19.
29: Canyonlands National Park
2020 visitors: 493,914
The unique combination of flat land, mountains and rivers that make up Utah's Canyonlands make it a popular destination for hikers, bikers and rafters.
But the park's spectacular canyons and trials present risk: In 2003, climber Aron Ralston's arm was pinned under a boulder, forcing him to amputate it himself — inspiring the movie "127 Hours."
28: Lassen Volcanic National Park
2020 visitors: 542,274
Located in one of the hottest and driest parts of California, Lassen is home to the largest plug dome volcano in the world, the still-active Lassen Peak.
It may not be the most heavily trafficked park, but its features have some of the best names around: the lava domes Chaos Crags and Jumbles; the giant hot springs field Bumpass Hell; the Devil's Kitchen trail; and a hiking area so devastated by past eruptions that it's simply called the Devastated Area.
27: Theodore Roosevelt National Park
2020 visitors: 551,303
The only such park named after one person, Theodore Roosevelt National Park in western North Dakota pays tribute to the man who did more to protect America's sprawling natural beauty than any other political figure. The park is popular among locals and tourists for its long hikes, scenic drives, foot and horse trails and abundant wildlife.
But those animals carry risks — particular the bison, which can be aggressive with humans.
26: Hawaii Volcanoes National Park
2020 visitors: 589,775
Making up a large part of the Big Island, the park is home to two active volcanoes: Kīlauea and Mauna Loa, the world's biggest shield volcano.
Kilauea is so active that from 1983 until 2018, it almost continuously spewed ash and lava, ending in a spectacular eruption in May 2018 that closed most of the park for months. Since then, the volcano has been quiet and Mauna Loa hasn't erupted since 1984.
25: Crater Lake National Park
2020 visitors: 670,500
Oregon's Crater Lake is the deepest in the United States, but you definitely don't want to swim in it without the proper gear. The water is freezing cold — an average of 38 degrees Fahrenheit.
Only one part of the lake allows swimming. Still, you can swim across the lake if you really want to. A pair of swimmers made the 12-mile trip to and from the main dock in 2012.
24: Everglades National Park
2020 visitors: 702,319
Found at the southern tip of Florida, Everglades is the largest tropical wilderness in the United States, and was created to protect the swampland from being drained for logging.
The vast wetlands and forests are under constant threat from urban development, extreme weather, pollution, and invasive animal species. Burmese pythons are a particular problem, and every so often, a local makes news for capturing a gigantic one — such as a 100-pound specimen caught near the park in June 2020.
23: Saguaro National Park
2020 visitors: 762,226
Designed to preserve the rare cacti of the Arizona desert, Saguaro has a major city, Tucson, and an interstate running down its middle.
The park is threatened by sprawl from the city, and sees tens of thousands of animals run over by cars on the interstate. It's also a fragile environment that's easily disturbed.
22: Sequoia National Park
2020 visitors: 796,086
World-famous for its gigantic trees, Sequoia in California is home to the tallest tree in the world, the towering General Sherman.
It's also home to caves, rock formations and endangered animals, particularly black bears. Encounters between these animals and humans are rare and are usually limited to bears looking for food. Even so, the park's website has a detailed description of what to do if you find yourself nose-to-nose with one.
21: Death Valley National Park
2020 visitors: 820,023
Despite being the hottest and driest national park, California's legendary Death Valley is always one of the most popular with visitors, thanks to its striking vistas, biking, camping and night skies.
But just because it's usually hot and dry doesn't mean it doesn't have extreme weather. In 2015, the park was hit with a storm that brought a year's worth of rain in a few hours. The "1,000-year flood" that followed closed off parts of the park for years.
20: Badlands National Park
2020 visitors: 916,932
Badlands is best known for its rolling hills, sharp peaks, its high numbers of American bison, and above all, its abundant fossil beds.
The park also faces challenges from climate change and the oil industry. The North Dakota oil boom put large drilling operations all around the park. And like Petrified Forest, Badlands has a problem with theft — in this case, the poaching of fossils.
19: Capitol Reef National Park
2020 visitors: 981,038
Utah's Capitol Reef has nothing to do with coral or water; it's a 65-million-year-old warp in Earth's crust, full of rock passages that early explorers called "reefs."
Known for its long stretches of desert punctuated by rock formations, the park is popular for hiking, backpacking and scenic drives. Locals particularly like it because it has many of the same features as nearby Zion National Park, but without the huge crowds.
18: Mount Rainier National Park
2020 visitors: 1,160,754
Made up almost entirely of protected wilderness, Washington's Mount Rainier attracts huge numbers of hikers, campers and wildlife watchers.
If you visit, keep an eye out for the adorable American pika.
17: Arches National Park
2020 visitors: 1,238,083
The park's iconic rock formations consistently make it one of the country's most popular tourist sites.
For that reason, the Arches is routinely overcrowded and beset by traffic jams.
16: Hot Springs National Park
2020 visitors: 1,348,215
Hot Springs was the first land in the United States to be reserved by the government for recreational use, predating the National Park System itself.
Visitors come to the Arkansas park to soak in the boiling waters, which once supported streets full of bathhouses; most of those are now gone. The park actually sits in the center of the town of Hot Springs, which grew up around the springs as a resort and has some of the best preserved 19th century architecture in the country.
15: Bryce Canyon National Park
2020 visitors: 1,464,655
While more remote than Utah's other parks, Bryce Canyon is famous for its long scenic drives, challenging hikes and for having some of the darkest night skies in the United States.
It was also one of the only national parks not to close completely during early coronavirus lockdowns, with some of its scenic vistas and trails staying open to visitors, even if all the amenities were closed.
14: Shenandoah National Park
2020 visitors: 1,666,265
This park is famous for numerous waterfalls, backcountry camping and its 100-mile Skyline Drive that winds through eight Virginia counties.
When part of it reopened over Memorial Day, visitors immediately returned and the park saw comparable numbers of cars on Skyline Drive versus previous years.
13: Glacier National Park
2020 visitors: 1,698,864
Montana's Glacier National Park runs right up to the Canadian border and usually draws millions of tourists from both countries.
But since some of the park sits on land that belongs to the Blackfeet Indian Reservation, park officials must work with tribe members to protect it. In 2020, visits dropped by roughly half.
11 (TIE) : Indiana Dunes National Park
2020 visitors: 2,293,106
Here's one of the country's more recent national parks, only getting the designation in early 2019. The area is renowned for its beaches and camping.
The Dunes was hugely crowded over Memorial Day weekend in 2020, seeing a big influx of coronavirus-weary tourists from Chicago.
11 (TIE): Yosemite National Park
2020 visitors: 2,293,106
Visits to this iconic California park dropped by half in 2020.
While fairly remote, Yosemite is one of America's best-known and best-loved parks. To manage coronavirus risks, the park is carefully managing reservations for visitors; reservations were expected to be required through September 30, 2021.
10: Joshua Tree National Park
2020 visitors: 2,399,542
Larger than the state of Rhode Island, Joshua Tree has breathtaking vistas.
If you plan on rock climbing in Joshua Tree during a summer 2021 visit, do your homework; many climbing sites are closed in the summer to protect nesting raptors.
9: Olympic National Park
2020 visitors: 2,499,177
Washington's Olympic National Park features everything from alpine mountains to rainforests to more than 70 miles of untouched coastline.
One interesting group of creatures the park is known for: slugs, including the banana slug.
8: Acadia National Park
2020 visitors: 2,669,034
Maine's Acadia is the only national park in the northeastern United States, and draws visitors from all over the region.
One of the park's most well-known features is Precipice Trail, a 1,000-foot straight-up climb called one of the hardest in the world.
7: Cuyahoga Valley National Park
2020 visitors: 2,755,628
Ohio's only national park has a unique mix of natural features, American history, sprawling wilderness, dense road networks and even several small towns inside its boundaries.
But, in 2020, with its millions of visitors not allowed in because of the pandemic, park staff had to get creative. The solution: "pop-up weddings," letting up to 10 socially-distanced visitors in for an intimate ceremony complete with decorations, cake and champagne.
6: Grand Canyon National Park
2020 visitors: 2,897,098
America's most Instagrammed park suffered a huge dip in 2020 visitors, perhaps, in part, because of the year-long closure of its east entrance. That entrance reopened in April 2021.
The Arizona landmark's breathtaking beauty is a natural fit for selfies, leading to all sorts of incidents and mishaps. Some are horrific, such as a woman who fell to her death in 2016 just moments after posting a picture. Others are much lighter, like the woman who found a one-star review of the canyon on Yelp (calling it "a very, very large hole") and posted it on Instagram to instant viral fame.
5: Grand Teton National Park
2020 visitors: 3,289,638
Located in Wyoming, just south of Yellowstone, Grand Teton is popular in its own right for climbing, fishing and backcountry camping. It's also known for its aggressive bears, that, unlike those in other parks, have no problem confronting humans.
In April 2021, a bizarre encounter at Grand Teton between a jogger and a black bear went viral.
4: Rocky Mountain National Park
2020 visitors: 3,305,199
Located in northern Colorado, Rocky Mountain is famous for its vast array of hiking trails, from easy walks to brutal backcountry routes only suitable for experienced hikers.
It also has a variety of climbs that bring their own dangers. In one bizarre case in 2012, a man was found guilty of pushing his wife to her death off a 130-foot drop in Rocky Mountain and claiming she fell; evidence showed he had scouted the area several times and marked an "x" on the exact spot.
3: Zion National Park
2020 visitors: 3,591,254
Utah's Zion was closed for part of 2020. The result was that animals went back to their natural routines, weren't bothering people for food and some went venturing into areas that animals rarely go into.
Visitors may catch sight of Mexican spotted owls, California condors or Mojave desert tortoises.
2: Yellowstone National Park
2020 visitors: 3,806,306
As America's first national park, Wyoming's Yellowstone is known for everything from its legendary geysers to the supervolcano it sits atop.
But most of all, it's famous for bears. While bear attacks against humans are rare – eight people have been killed by bears in the park's whole existence — when it comes to salvos against other animals, all bets are off.
In May 2020, as the park was reopening, a video of a bear and bison fighting it out on a river bank went viral. The bear won.
1: Great Smoky Mountains National Park
2020 visitors: 12,095,720
America's most visited national park, Great Smoky Mountains straddles Tennessee and North Carolina, and features everything from mountains and waterfalls to hiking trails and historical attractions.
Most visitors enter the park through Sevier County, Tennessee, and while there, many make a stop at Dollywood. Dolly Parton's theme park draws 3 million people every year, and its success goes hand in hand with the success of the park.