Yellowstone became a national park in 1872, but Congress had protected the hot springs of Arkansas forty years earlier. These stories cover the parks, their wildlife, their geology and the people behind them: soldiers who patrolled on skis, a hot-pool microbe that changed DNA science, a newspaper-wrapped lunch that led to Crater Lake, and fireflies so popular that a lottery decides who gets to watch.
Every tile in a U.S. National Parks game carries one of these. Open one to read it now, or leave them for the board to hand you.
Parks
nine stories
1When the cavalry ran Yellowstone
On the tile: Yellowstone1886-1918
Congress created Yellowstone in 1872 but gave it no money for upkeep until 1878, and the park was poorly protected. In August 1886, Company M of the 1st U.S. Cavalry arrived and set up camp at Mammoth Hot Springs. Soldiers patrolled on horseback in summer and on skis in winter, fought fires and caught poachers. At the Army's peak in 1910, 324 soldiers were stationed there. The cavalry stayed until 1918, and most Army-era buildings still stand, now serving as park headquarters.
Yellowstone was not alone for long. On March 3, 1875, President Ulysses S. Grant signed a law making part of Michigan's Mackinac Island the nation's second national park. Senator Thomas Ferry, born on the island, had pushed the idea. The government already owned the land, and Army troops at Fort Mackinac were on hand to care for it. The arrangement lasted about 20 years. In 1895 the federal government transferred the park to Michigan, and it became Mackinac Island State Park, the state's first.
In 1820, Arkansas's territorial legislature asked that its hot springs be set aside as a federal reservation. On April 20, 1832, President Andrew Jackson signed the law, forty years before Yellowstone became a national park. It took until 1921 for Hot Springs itself to be named a national park. The water starts as rain that sinks 4,500 to 7,500 feet, travels for over 4,000 years, then rises along a fault at about 143 degrees Fahrenheit. The park still gives it away free at its jug fountains.
The National Park of American Samoa is the only U.S. national park south of the equator, and it is unusual in another way: the federal government does not own its land. Samoan tradition holds land communally, so the National Park Service leases it from village councils. Congress established the park in 1988, but the 50-year lease with eight villages was not signed until 1993. Its rainforests and reefs lie on the islands of Tutuila, Ta'u and Ofu, where large fruit bats called flying foxes coast above forested ridges.
5The smallest national park and its old, forgotten name
On the tile: Gateway Arch2018
Gateway Arch National Park in St. Louis is the smallest national park in the United States, and for most of its life it went by another name. The site was designated the Jefferson National Expansion Memorial in 1935, long before its arch was designed in 1947 or completed in 1965. Studies showed that name had never caught on with the public, so in 2018 it became Gateway Arch National Park. The 630-foot stainless steel Arch is America's tallest man-made monument.
6A park as big as Yellowstone, Yosemite and Switzerland
On the tile: Wrangell1980
Wrangell-St. Elias National Park and Preserve, established in 1980, is the largest national park in the United States at about 13.2 million acres. The Park Service puts that in perspective: it is the same size as Yellowstone, Yosemite and Switzerland combined. The park rises from the ocean to 18,008 feet and holds the greatest concentration of glaciers in North America, more than 3,000 of them covering over three million acres. Inside it sits Kennecott, an early 1900s copper mining operation in the heart of the Alaskan wilderness.
In 1919, Maine's Sieur de Monts National Monument became Lafayette National Park. The name lasted not quite ten years. The family of the late John Godfrey Moore held thousands of acres on the Schoodic Peninsula, and superintendent George Dorr wrote of the Moore daughters' "objection to the name of Lafayette." When Congress let the park add new lands in January 1929, it also gave it a new name: Acadia. The story goes that the daughters disliked a name honoring the French, but Dorr's biographer knows of no source that says so.
8The first national park created to protect human history
On the tile: Mesa Verde1906
Earlier national parks were created mainly to preserve natural landscapes and wildlife. Mesa Verde, in southwestern Colorado, was the first created to protect structures people built. At the start of the 20th century, archaeological sites across the Southwest were being plundered by rogue excavations. Theodore Roosevelt signed the park into law on June 29, 1906, three weeks after he signed the Antiquities Act. The park preserves nearly 5,000 archaeological sites left by Ancestral Puebloan people, including Cliff Palace, a collection of 150 rooms and 23 kivas tucked into a sandstone alcove.
9The unfinished fort where Dr. Mudd fought yellow fever
On the tile: Dry Tortugas1867
Fort Jefferson, the heart of Dry Tortugas National Park, is the largest all-masonry fort in the United States. Workers built it from 1846 to 1875, and it was never completed. After the Civil War it served as a federal prison. Among its prisoners was Dr. Samuel Mudd, the physician who set John Wilkes Booth's broken leg and was convicted of aiding him. When yellow fever broke out at the fort in 1867, Mudd helped the prison doctors fight the epidemic. In 1869 President Andrew Johnson pardoned him, and Mudd went home to his Maryland farm.
1Wolves return to Yellowstone, and their menu shifts
On the tile: Gray Wolves1995-1997
By the early 1900s, habitat loss and extermination programs had wiped out wolves across most of the United States. From 1995 to 1997, 41 wild wolves from Canada and northwest Montana were released in Yellowstone, and biologists watched what they hunted. From 1995 to 2000, elk calves made up half of the wolves' early-winter prey and bull elk a quarter; from 2001 to 2007 that ratio reversed. The park cautions that such shifts are tied to other factors too, including other predators, weather and how hoofed animals are managed outside the park.
Yellowstone is the only place in the United States where bison have lived continuously since prehistoric times, but it was a close call. By 1902, poaching had cut the park's herd to about two dozen animals. That year the U.S. Army, which was running the park, brought in 21 bison from two private herds to prevent the animals' extinction there. The rescue worked. Yellowstone now has the nation's largest bison population on public land, estimated at nearly 5,300 animals before calves were born in 2025.
Moose first arrived on Isle Royale in the early 1900s. Wolves are widely believed to have followed during the winter of 1948, crossing an ice bridge from the Canadian mainland. Scientists have studied the two for decades, in what the park calls the longest running large mammal predator-prey study on earth. Since 1980 the moose population has ranged from about 500 to 2,400. The isolated wolves suffered from inbreeding and fell to just two animals between 2016 and 2018, until nineteen wolves were relocated to the island from the Great Lakes region.
Devils Hole, a detached unit of Death Valley National Park, is a water-filled cavern cut into the side of a hill. It holds the only naturally occurring population of the endangered Devils Hole pupfish. The cavern is over 500 feet deep, and its bottom has never been mapped. Large earthquakes as far away as Japan, Indonesia and Chile have made its water slosh like a bathtub, with waves splashing as high as two meters up the walls.
The California condor is the largest land bird in North America, with a wingspan up to 9.5 feet. In 1982, fewer than two dozen were left in the world, and by 1987 every wild condor had been captured for breeding. The gamble worked. Releases began in California in 1992 and in Arizona in 1996, and condors now fly free in northern Arizona and southern Utah, including over the Grand Canyon. Lead is the big danger: they swallow fragments of lead ammunition while scavenging carcasses, and lead poisoning is their number one known cause of death.
From roughly late June through September, bears at Katmai National Park gorge on salmon, and large bears can gain a few hundred pounds of fat before denning. In 2014, ranger Mike Fitz was scrolling through comments on the explore.org live feed of Brooks Falls and helped dream up a one-day contest. Fat Bear Tuesday was held on September 30, with votes cast as likes on Facebook. The first full Fat Bear Week followed in 2015. The first champion, 480 Otis, won again in 2016, 2017 and 2021.
7Fireflies that flash in unison, and a lottery to see them
On the tile: FirefliesMay-June
Great Smoky Mountains National Park has 19 species of fireflies, but one draws crowds: the synchronous firefly, Photinus carolinus. For about two to three weeks a year, males flash together, five to eight flashes followed by an eight-second pause, while females on the forest floor respond. One theory is that the unison flashing helps males draw an answer from females. Since 1993, peak dates have fallen between the third week of May and the third week of June, and so many people come that the park runs a lottery for viewing at Elkmont.
The island fox, about the size of a housecat, lives only on six of California's eight Channel Islands. In the 1990s its numbers crashed on three islands in Channel Islands National Park. Golden eagles had settled there, drawn by non-native hoofed animals as a food source and helped by the DDT-caused decline of bald eagles, their natural competitor. By 2000, about 15 foxes remained on each of San Miguel and Santa Rosa. In 1999 the park began captive breeding, removing golden eagles, bringing back bald eagles and removing non-native hoofed animals. The IUCN now lists the island fox as near threatened.
South Florida is the only place where American alligators and American crocodiles live together, and Everglades National Park has both. Salt helps sort them. Crocodiles inhabit coastal, brackish and salt water, while alligators lack the salt-secreting glands that crocodiles have. To tell them apart, look at the head: a crocodile has a narrow, triangular snout, lighter skin and a fourth tooth on each side of the lower jaw that shows when its mouth is closed. The park calls alligators a keystone species; their holes hold water all year except in severe drought.
Since its formal discovery in 1870, Old Faithful has been one of the more predictable geysers, but it does not run like a clock. As of January 2025, the median interval between eruptions was 102 minutes, give or take 10, with intervals ranging from 54 to 118 minutes. Eruptions last one and a half to five minutes and reach anywhere from 106 to more than 180 feet. Old Faithful is one of nearly 500 geysers in Yellowstone, which has close to 60 percent of the world's geysers, and one of six that rangers currently predict.
2Why no dinosaur bones turn up at the Grand Canyon
On the tile: Grand Canyon5-6 million years ago
Dinosaur hunters are out of luck at the Grand Canyon: its rocks are older than the oldest known dinosaurs. Instead the canyon holds marine fossils such as trilobites, crinoids and brachiopods, and the Coconino Sandstone preserves tracks of ancient scorpions, millipedes and mammal-like reptiles. The igneous and metamorphic rocks of the inner gorge formed almost two billion years ago, and even the Kaibab Limestone at the rim is 270 million years old. The canyon itself is young. The Colorado River began carving its way down just 5 to 6 million years ago.
3The Old Man of the Lake, a log adrift since at least 1896
On the tile: Crater Lake1896
Crater Lake, the deepest lake in the United States, formed after a massive eruption of Mount Mazama about 7,700 years ago, and over several hundred years rain and snow partly filled the caldera. One of its oddest residents is the Old Man of the Lake, a 30-foot mountain hemlock log that drifts around the lake standing upright, with three feet above the water. Geologist Joseph Diller first sighted and tracked it in 1896. Carbon dating shows the log is more than 450 years old.
4How the world's longest cave keeps getting longer
On the tile: Mammoth Cave1972
Kentucky's Mammoth Cave is the world's longest known cave system, and it keeps growing on the map. In 1908, German engineer Max Kämper mapped the cave for the Mammoth Cave Estate and found numerous new passages. In 1972, explorers found a connection between the Mammoth Cave Ridge and Flint Ridge cave systems, making 144 miles of passages, the longest known system in the world. Surveying went on. On February 15, 2013, the cave was officially mapped at 400 miles, and the network now stretches over 400 miles.
The General Sherman Tree in Sequoia National Park is the largest tree in the world by volume, an estimated 52,500 cubic feet. In lumber terms that is probably 630,000 board feet, which the park says could build 120 average-sized houses. Its trunk alone weighs nearly 1,400 tons. It is not the tallest tree, though. It stands 274.9 feet, and that title belongs to a redwood named Hyperion. Giant sequoias keep bulking up: in one year a mature one adds enough wood to make a sixty-foot-tall oak three feet across.
On Racetrack Playa in Death Valley National Park, rocks leave long trails across the lakebed with nobody pushing them. In December 2013, researchers found the playa under a shallow pond only a few inches deep. At night it froze into thin windowpane ice. On sunny days the ice broke into floating panels that light winds of about 10 miles per hour drove across the pond, shoving rocks ahead of them. The team also saw grounding ice panels carve rock-less trails, which the Park Service had once suspected were caused by tourists stealing rocks.
7Ice, hoodoos and the settler behind Bryce's Canyon
On the tile: Hoodoos1875-1880
Bryce Canyon National Park has the largest concentration of hoodoos, irregular columns of rock, found anywhere on Earth. Ice does much of the carving. On over 170 nights a year, temperatures go both above and below freezing, and water in cracks expands by 9 percent as it freezes, wedging rock apart. The name came from a settler. Ebenezer Bryce arrived in 1875 and built a road into the pink cliffs to reach timber, and people called the amphitheater where it ended Bryce's Canyon. He moved away in 1880, but the name stuck.
8Ice Age footprints beside the world's largest gypsum dunes
On the tile: White Sands21,000-23,000 years ago
White Sands National Park preserves more than half of the largest gypsum dunefield in the world. It also has the largest collection of fossilized human footprints, left in an Ice Age landscape shared with Columbian mammoths and ground sloths. Radiocarbon dating of seeds found with some of the human tracks puts them at roughly 21,000 to 23,000 years old. In 2018, researchers found tracks they believe a female left while walking for almost a mile, with a toddler's footprints occasionally showing up beside hers.
Arches National Park has over 2,000 documented arches, from sliver-thin cracks to spans greater than 300 feet, and the recipe starts with a thick layer of salt deep underground. Squeezed by the rock above, the salt flowed and bulged upward into long domes, and the rock on top cracked like the surface of freshly baked bread. Rainwater soaks into the porous Entrada Sandstone and dissolves the calcite bonding its sand, rotting the rock from the inside out. That so many still stand shows the area has been fairly stable for at least 50,000 years.
1The first Black superintendent of a national park
On the tile: Charles Young1903
In the summer of 1903, Captain Charles Young and his troops were tasked with managing Sequoia National Park, making him the first African American national park superintendent. His Buffalo Soldiers built roads and trails that other troops had been unable to finish in the years before. Young had already become only the third African American to graduate from West Point. After he was medically retired in 1917, he rode 500 miles on horseback from Wilberforce, Ohio, to Washington, D.C., to demonstrate his fitness to serve. In 2021 he was posthumously promoted to brigadier general.
Stephen Bishop, an enslaved African American man, arrived at Mammoth Cave in 1838 and began guiding as a teenager. After he and a visitor crossed an obstacle called the Bottomless Pit, many miles of the cave's labyrinth opened to exploration. In 1842, during a visit to Locust Grove in Louisville, he drew a map of the explored passages from memory. He once described the cave as "a grand, gloomy and peculiar place." He eventually gained his freedom and died in 1857. Decades later a visitor from Pittsburgh gave him a gravestone.
3The writer who called the Everglades a river of grass
On the tile: M. S. Douglas1947
Marjory Stoneman Douglas came to Miami in 1915 to work for her father at the Miami Herald, starting as a society reporter. Her book The Everglades: River of Grass came out in 1947, the year Everglades National Park was established, and it became the definitive description of the place. Long before scientists became alarmed, she railed at officials as canals and levees destroyed wetlands. In 1970 she formed Friends of the Everglades. Writer John Rothchild said her voice "had the sobering effect of a one-room schoolmarm's."
4Forty-five miles of roads where cars are not allowed
On the tile: Rockefeller1913-1940
John D. Rockefeller Jr. was a skilled horseman, and he wanted to travel by horse and carriage on motor-free roads into the heart of Mount Desert Island. So he built them. From 1913 to 1940 he laid out broken-stone carriage roads, shaped to follow the contours of the land, save trees and catch scenic views. Forty-five miles of them now wind through Acadia National Park. Granite coping stones line the edges as guardrails, affectionately called Rockefeller's teeth. Walkers, cyclists and horse-drawn carriages share the roads, and cars still stay out.
5The teacher who became Yosemite's first woman ranger
On the tile: Clare Hodges1918
Clare Marie Hodges began teaching at the Yosemite Valley School in 1916. During World War I she heard the park was struggling to find men to work as rangers. In the spring of 1918 she went to Superintendent Washington B. Lewis and said, "Probably you'll laugh at me, but I want to be a ranger." Lewis, it turned out, had already considered the idea. She became the first woman ranger in Yosemite. One of her jobs was carrying the gate receipts from Tuolumne Meadows to park headquarters, an overnight ride on horseback.
6The lunch-wrapper article that led to Crater Lake
On the tile: William Steel1870-1902
In 1870 a young man from Kansas named William Gladstone Steel unwrapped his lunch and read the newspaper it came in. An article about an unusual lake in Oregon sparked his imagination, and he vowed to see it. Thirteen years after his family moved to Portland, he finally did, and decided Crater Lake should be a public park forever. In 1886 he helped a survey that sounded the lake with pipe and piano wire. Sheep herders and mining interests argued against him, but on May 22, 1902, Crater Lake became a national park.
On June 8, 1906, Theodore Roosevelt signed the Antiquities Act, which gave presidents the authority to designate national monuments. He used it 18 times, starting that same year with sites such as Devils Tower in Wyoming. He already knew the Grand Canyon. Speaking there in 1903, he had urged his listeners to "keep this great wonder of nature as it now is." When Congress fought his efforts to create a national park at the canyon, Roosevelt used his executive power and made it a national monument in 1908. The Grand Canyon is a national park today.
8Yosemite's great champion started out herding sheep
On the tile: John Muir1868-1914
John Muir first visited Yosemite in 1868 and was so impressed that he returned the next year, taking a job at $30 a month guiding 2,000 sheep to Tuolumne Meadows. He then worked two years at a sawmill. His campaigning helped make Yosemite a national park in 1890, he was the Sierra Club's president from its creation in 1892, and in 1903 he toured President Theodore Roosevelt through the park. His fight against a dam in the Hetch Hetchy Valley failed. Muir died on Christmas Eve 1914, just over a year after Congress authorized the dam.
9The teenage cowhand who became Mr. Carlsbad Caverns
On the tile: Jim White1898
In 1898, a 16-year-old Texas-born cowhand named Jim White probably entered Carlsbad Cavern for the first time, though who first found the entrance is still disputed. In 1923 he guided a government survey that recommended the cavern become a national monument, and it did later that year. Early visitors had to ride down in a guano bucket until a staircase was installed in 1925. White kept exploring and guiding, and from 1937 he sold his ghostwritten book inside the cave. He died in 1946, known unofficially as Mr. Carlsbad Caverns.