Yellowstone National Park is a United States National Park and a UNESCO World Heritage Site. It was the world’s first national park, set aside in 1872 to preserve the vast number of geysers, hot springs, and other thermal areas, as well as to protect the incredible wildlife and rugged beauty of the area.
The park is principally contained within the northwest corner of Wyoming, but also extends into the states of Idaho and Montana. Yellowstone National Park, set aside by the U.S. Congress as a national park on March 1, 1872, is located mostly in the U.S. state of Wyoming, though it also extends into Montana and Idaho.
The park was the first of its kind, and is known for its wildlife and its many geothermal features, especially Old Faithful Geyser, one of the most popular areas in the park. It has many types of ecosystems, but the subalpine forest is dominant.
Aboriginal Americans have lived in the Yellowstone region for at least 11,000 years. The region was bypassed during the Lewis and Clark Expedition in the early 1800s. Aside from visits by mountain men during the early to mid-1800s, organized exploration did not begin until the late 1860s. The U.S. Army was commissioned to oversee the park just after its establishment. In 1917, administration of the park was transferred to the National Park Service, which had been created the previous year. Hundreds of structures have been built and are protected for their architectural and historical significance, and researchers have examined more than 1,000 archaeological sites.
Yellowstone National Park spans an area of 3,468 square miles (8,983 km²), comprising lakes, canyons, rivers and mountain ranges. Yellowstone Lake is one of the largest high-altitude lakes in North America and is centered over the Yellowstone Caldera, the largest supervolcano on the continent. The caldera is considered an active volcano; it has erupted with tremendous force several times in the last two million years.
Half of the world’s geothermal features are in Yellowstone, fueled by this ongoing volcanism. Lava flows and rocks from volcanic eruptions cover most of the land area of Yellowstone. The park is the centerpiece of the Greater Yellowstone Ecosystem, the largest remaining, nearly-intact ecosystem in the Earth’s northern temperate zone.
Hundreds of species of mammals, birds, fish and reptiles have been documented, including several that are either endangered or threatened. The vast forests and grasslands also include unique species of plants. Grizzlies, wolves, and free-ranging herds of bison and elk live in the park. Forest fires occur in the park each year; in the large forest fires of 1988, nearly one third of the park burned.
Yellowstone has numerous recreational opportunities, including hiking, camping, boating, fishing and sightseeing. Paved roads provide close access to the major geothermal areas as well as some of the lakes and waterfalls. During the winter, visitors often access the park by way of guided tours that use either snow coaches or snowmobile.
Yellowstone is the first and oldest national park in the world and covers 3,472 square miles (8,987 km²), mostly in the northwest corner of Wyoming. The park is famous for its various geysers, hot springs, and other geothermal features and is home to grizzly bears and wolves, and free-ranging herds of bison and elk.
Long before any recorded human history in Yellowstone, a massive volcanic eruption spewed an immense volume of ash that covered all of the western U.S., much of the Midwest, northern Mexico and some areas of the eastern Pacific Coast. The eruption dwarfed that of Mt. St. Helens in 1980 and left a huge caldera. Yellowstone typically erupts every 600,000 to 900,000 years with the last event occurring 640,000 years ago. Its eruptions are among the largest known to have ever occurred on Earth, producing drastic climate change in the aftermath.
The park was named for the yellow rocks seen in the Grand Canyon of the Yellowstone – a deep gash in the Yellowstone Plateau that was formed by floods during previous ice ages and by river erosion from the Yellowstone River. In 1872, Yellowstone became the first National Park reserve declared anywhere in the world, by President Ulysses S. Grant. In 1978 it was designated a World Heritage Site by UNESCO.
The first detailed expedition to the Yellowstone area was the Folsom Expedition of 1869, which consisted of three privately funded explorers. The Folsom party followed the Yellowstone River to Yellowstone Lake. The members of the Folsom party kept a journal and based on the information it reported, a party of Montana residents organized the Washburn-Langford-Doane Expedition in 1870. It was headed by the surveyor-general of Montana Henry Washburn, and included Nathaniel P. Langford (who later became known as “National Park” Langford) and a U.S. Army detachment commanded by Lt. Gustavus Doane.
The expedition spent about a month exploring the region, collecting specimens, and naming sites of interest. A Montana writer and lawyer named Cornelius Hedges, who had been a member of the Washburn expedition, proposed that the region should be set aside and protected as a National Park; he wrote a number of detailed articles about his observations for the Helena Herald newspaper between 1870 and 1871. Hedges essentially restated comments made in October 1865 by acting Montana Territorial Governor Thomas Francis Meagher, who had previously commented that the region should be protected. Others made similar suggestions. In an 1871 letter from Jay Cooke to Ferdinand Hayden, Cooke wrote that his friend, Congressman William D. Kelley had also suggested “Congress pass a bill reserving the Great Geyser Basin as a public park forever”.
Geological characteristics form the foundation of an ecosystem. In Yellowstone, the interplay between volcanic, hydrothermal, and glacial processes and the distribution of flora and fauna are intricate and unique. The topography of the land from southern Idaho northeast to Yellowstone results from millions of years of hotspot influence. Some scientists believe the Yellowstone Plateau itself is a result of uplift due to hotspot volcanism.
Approximately 96 percent of the land area of Yellowstone National Park is located within the state of Wyoming. Another 3 percent is within Montana, with the remaining 1 percent in Idaho. The park is 63 miles (102 km) north to south, and 54 miles (87 km) west to east by air. At 2,219,789 acres (898,317 ha/3,468.420 sq mi), Yellowstone is larger than the states of Rhode Island and Delaware combined. Rivers and lakes cover 5 percent of the land area, with the largest water body being Yellowstone Lake at 87,040 acres (35,220 ha/136.00 sq mi). Yellowstone Lake is up to 400 feet (122 m) deep and has 110 miles (177 km) of shoreline. At an elevation of 7,733 feet (2,357 m) above sea level, Yellowstone Lake is the largest high altitude lake in North America. Forests comprise 80 percent of the land area of the park; most of the rest is grassland.
The Continental Divide of North America runs diagonally through the southwestern part of the park. The divide is a topographic feature that separates Pacific Ocean and Atlantic Ocean water drainages. About one third of the park lies on the west side of the divide. The origins of the Yellowstone and Snake Rivers are near each other but on opposite sides of the divide. As a result, the waters of the Snake River flow to the Pacific Ocean, while those of the Yellowstone find their way to the Atlantic Ocean via the Gulf of Mexico.
The park sits on the Yellowstone Plateau, at an average altitude of 8,000 feet (2,400 m) above sea level. The plateau is bounded on nearly all sides by mountain ranges of the Middle Rocky Mountains, which range from 9,000 to 11,000 feet (2,743 to 3,352 m) in elevation. The highest point in the park is atop Eagle Peak (11,358 ft/3,462 m) and the lowest is along Reese Creek (5,282 ft/1,610 m). Nearby mountain ranges include the Gallatin Range to the northwest, the Beartooth Mountains in the north, the Absaroka Range to the east, and the Teton Range and the Madison Range to the southwest and west. The most prominent summit on the Yellowstone Plateau is Mount Washburn at 10,243 feet (3,122 m).
Yellowstone National Park has one of the world’s largest petrified forests, trees which were long ago buried by ash and soil and transformed from wood to mineral materials. There are 290 waterfalls of at least 15 feet (4.5 m) in the park, the highest being the Lower Falls of the Yellowstone River at 308 feet (94 m).
Two deep canyons are located in the park, cut through the volcanic tuff of the Yellowstone Plateau by rivers over the last 640,000 years. The Lewis River flows through Lewis Canyon in the south, and the Yellowstone River has carved the colorful Grand Canyon of the Yellowstone in its journey north.
The park is the core of the Greater Yellowstone Ecosystem, one of the largest intact temperate zone ecosystems remaining on the planet. Black bears, grizzly bears, deer, elk, bison, bighorn sheep and wolves can all be found within the park borders. Geothermal features include geysers, mud pots, hot springs, fumaroles, and others. This is all because of the active volcano that Yellowstone sits on top of. Geothermal features are formed from superheated water heated by the volcano. The pressure is so intense that it gets released into the air as hundreds of gallons of steaming water, or, when the pressure is not as intense, hot springs or mud pots are formed. Various colors of the pool are due to different types of bacteria growing in different temperatures.
The most famous geyser in the park, and perhaps the world, is Old Faithful Geyser, located in Upper Geyser Basin, where Castle Geyser, Lion Geyser and Beehive Geyser are considered ones of the most beautiful geysers in the world; the park also contains the largest active geyser in the world—Steamboat Geyser in the Norris Geyser Basin. There are 300 geysers in Yellowstone and a total of at least 10,000 geothermal features altogether. Half the geothermal features and two-thirds of the world’s geysers are concentrated in Yellowstone.
Yellowstone experiences thousands of small earthquakes every year, virtually all of which are undetectable to people. There have been six earthquakes with at least magnitude 6 or greater in historical times, including a 7.5 magnitude quake that struck just outside the northwest boundary of the park in 1959. This quake triggered a huge landslide, which caused a partial dam collapse on Hebgen Lake; immediately downstream, the sediment from the landslide dammed the river and created a new lake, known as Earthquake Lake.
1,700 species of trees and other vascular plants are native to the park. Another 170 species are considered to be exotic species and are non-native. Of the eight conifer tree species documented, Lodgepole Pine forests cover 80% of the total forested areas. Other conifers, such as Subalpine Fir, Engelmann Spruce, Rocky Mountain Douglas-fir and Whitebark Pine, are found in scattered groves throughout the park. As of 2007, the whitebark pine is threatened by a fungus known as white pine blister rust; however, this is mostly confined to forests well to the north and west. In Yellowstone, about seven percent of the whitebark pine species have been impacted with the fungus, compared to nearly complete infestations in northwestern Montana. Quaking Aspen and willows are the most common species of deciduous trees. The aspen forests have declined significantly since the early 20th century, but scientists at Oregon State University attribute recent recovery of the aspen to the reintroduction of wolves which has changed the grazing habits of local elk.
There are dozens of species of flowering plants that have been identified, most of which bloom between the months of May and September. The Yellowstone Sand Verbena is a rare flowering plant found only in Yellowstone. It is closely related to species usually found in much warmer climates, making the sand verbena an enigma. The estimated 8,000 examples of this rare flowering plant all make their home in the sandy soils on the shores of Yellowstone Lake, well above the waterline.
In Yellowstone’s hot waters, bacteria form mats of bizarre shapes consisting of trillions of individuals. These bacteria are some of the most primitive life forms on earth. Flies and other arthropods live on the mats, even in the middle of the bitterly cold winters. Initially, scientists thought that microbes there gained sustenance only from sulfur. In 2005, researchers from the University of Colorado at Boulder discovered that the sustenance for at least some of the diverse hyperthermophilic species is molecular hydrogen.
Thermus aquaticus is a bacterium found in the Yellowstone hot springs produces an important enzyme that is easily replicated in the lab and is useful in replicating DNA as part of the polymerase chain reaction (PCR) process. The retrieval of these bacteria can be achieved with no impact to the ecosystem. Other bacteria in the Yellowstone hot springs may also prove useful to scientists who are searching for cures for various diseases.
Non-native plants sometimes threaten native species by using up nutrient resources. Though exotic species are most commonly found in areas with the greatest human visitation, such as near roads and at major tourist areas, they have also spread into the backcountry. Generally, most exotic species are controlled by pulling the plants out of the soil or by spraying, both of which are time consuming and expensive.
Yellowstone is widely considered to be the finest megafauna wildlife habitat in the lower 48 states. There are almost 60 species of mammals in the park, including the endangered gray wolf, the threatened lynx, and grizzly bears. Other large mammals include the bison (buffalo), black bear, elk, moose, mule deer, mountain goat, pronghorn, bighorn sheep and mountain lion.
The relatively large bison populations are a concern for ranchers, who fear that the species can transmit bovine diseases to their domesticated cousins. In fact, about half of Yellowstone’s bison have been exposed to brucellosis, a bacterial disease that came to North America with European cattle that may cause cattle to miscarry.
The disease has little effect on park bison, and no reported case of transmission from wild bison to domestic livestock has been filed. However, the Animal and Plant Health Inspection Service (APHIS) has stated that Bison are the “likely source” of the spread of the disease in cattle in Wyoming and North Dakota. Elk also carry the disease and are believed to have transmitted the infection to horses and cattle.
Bison once numbered between 30 and 60 million individuals throughout North America, and Yellowstone remains one of their last strongholds. Their populations had increased from less than 50 in the park in 1902 to 4,000 by 2003. The park’s bison population reached a peak in 2005 with 4,900 animals.
After a summer estimated population of 4,700 in 2007, the number dropped to 3,000 in 2008 after a harsh winter and controversial brucellosis management sending hundreds to slaughter. The Yellowstone herd is believed to be one of only four free roaming and genetically pure herds on public lands in North America. The other three herds are in the Henry Mountains of Utah, Wind Cave National Park in South Dakota and on Elk Island in Alberta, Canada.
To combat the perceived threat, national park personnel regularly harass bison herds back into the park when they venture outside of the area’s borders. During the winter of 1996–97, the bison herd was so large that 1,079 bison that had exited the park were shot or sent to slaughter. Animal rights activists argue that this is a cruel practice and that the possibility for disease transmission is not as great as some ranchers maintain. Ecologists point out that the bison are merely traveling to seasonal grazing areas that lie within the Greater Yellowstone Ecosystem that have been converted to cattle grazing, some of which are within National Forests and are leased to private ranchers. APHIS has stated that with vaccinations and other means, brucellosis can be eliminated from the bison and elk herds throughout Yellowstone.
After the wolves were extirpated from Yellowstone, the coyote then became the park’s top canine predator. However, the coyote is not able to bring down large animals, and the result of this lack of a top predator on these populations was a marked increase in lame and sick megafauna. Starting in 1914, in an effort to protect elk populations, the U.S. Congress appropriated funds to be used for the purposes of “destroying wolves, prairie dogs, and other animals injurious to agriculture and animal husbandry” on public lands. Park Service hunters carried out these orders, and by 1926 they had killed 136 wolves, and wolves were virtually eliminated from Yellowstone. Further exterminations continued until the National Park Service ended the practice in 1935. With the passing of the Endangered Species Act in 1973, the wolf was one of the first mammal species listed.
By the 1990s, the Federal government had reversed its views on wolves. In a controversial decision by the U.S. Fish and Wildlife Service (which oversees threatened and endangered species), Mackenzie Valley wolves, imported from Canada, were reintroduced into the park. Reintroduction efforts have been successful with populations remaining relatively stable. A survey conducted in 2005 reported that there were 13 wolf packs, totaling 118 individuals in Yellowstone and 326 in the entire ecosystem. These park figures were lower than those reported in 2004 but may be attributable to wolf migration to other nearby areas as suggested by the substantial increase in the Montana population during that interval. Almost all the wolves documented were descended from the 66 wolves reintroduced in 1995–96. The recovery of populations throughout the states of Wyoming, Montana and Idaho has been so successful that on Feb 27, 2008 the U.S. Fish and Wildlife Service removed the Northern Rocky Mountain wolf population from the endangered species list.
An estimated 600 grizzly bears live in the Greater Yellowstone Ecosystem, with more than half of the population living within Yellowstone. The grizzly is currently listed as a threatened species, however the U.S. Fish and Wildlife Service has announced that they intend to take it off the endangered species list for the Yellowstone region but will likely keep it listed in areas where it has not yet recovered fully. Opponents of delisting the grizzly are concerned that states might once again allow hunting and that better conservation measures need to be implemented to ensure a sustainable population.
Population figures for elk are in excess of 30,000—the largest population of any large mammal species in Yellowstone. The northern herd has decreased enormously since the mid-1990s, and this has been attributed to wolf predation and causal effects such as elk using more forested regions to evade predation, consequently making it harder for researchers to accurately count them. The northern herd migrates west into southwestern Montana in the winter. The southern herd migrates southward, and the majority of these elk winter on the National Elk Refuge, immediately southeast of Grand Teton National Park. The southern herd migration is the largest mammalian migration remaining in the U.S. outside of Alaska.
In 2003, the tracks of one female lynx and her cub were spotted and followed for over 2 miles (3.2 km). Fecal material and other evidence obtained were tested and confirmed to be those of a lynx. No visual confirmation was made, however. Lynx have not been seen in Yellowstone since 1998, though DNA taken from hair samples obtained in 2001 confirmed that lynx were at least transient to the park. Other less commonly seen mammals include the mountain lion and wolverine. The mountain lion has an estimated population of only 25 individuals parkwide. The wolverine is another rare park mammal, and accurate population figures for this species are not known. These uncommon and rare mammals provide insight into the health of protected lands such as Yellowstone and help managers make determinations as to how best to preserve habitats.
Eighteen species of fish live in Yellowstone, including the core range of the Yellowstone cutthroat trout—a fish highly sought by anglers. The Yellowstone cutthroat trout has faced several threats since the 1980s, including the suspected illegal introduction into Yellowstone Lake of lake trout, an invasive species which consume the smaller cutthroat trout. Although lake trout were established in Shoshone and Lewis lakes in the Snake River drainage from U.S. Government stocking operations in 1890, it was never officially introduced into the Yellowstone River drainage.
The cutthroat trout has also faced an ongoing drought, as well as the accidental introduction of a parasite whirling disease which causes a terminal nervous system disease in younger fish. Since 2001, all native sport fish species caught in Yellowstone waterways are subject to a catch and release law. Yellowstone is also home to six species of reptiles, such as the painted turtle and western rattlesnake, and four species of amphibians, including the Boreal Chorus Frog.
311 species of birds have been reported, almost half of which nest in Yellowstone. As of 1999, twenty-six pairs of nesting bald eagles have been documented. Extremely rare sightings of whooping cranes have been recorded, however only three examples of this species are known to live in the Rocky Mountains, out of 385 known worldwide. Other birds, considered to be species of special concern because of their rarity in Yellowstone, include the common loon, harlequin duck, osprey, peregrine falcon and the trumpeter swan.
The weather in Yellowstone National Park can change very rapidly from sunny and warm to cold and rainy, so it’s important to bring along extra layers of clothing which can be used as needed.
- Summer: Daytime temperatures are often in the 70s (25°C) and occasionally in the 80s (30°C) in lower elevations. Nights are usually cool and temperatures may drop below freezing at higher elevations. Thunderstorms are common in the afternoons.
- Winter: Temperatures often range from zero to 20°F(-20°C to -5°C) throughout the day. Sub-zero temperatures over-night are common. The record low temperature is -66F (-54°C). Snowfall is highly variable. While the average is 150 inches per year, it is not uncommon for higher elevations to get twice that amount.
- Spring & Fall: Daytime temperatures range from the 30s to the 60s (0 to 20°C) with overnight lows in the teens to single digits (-5 to -20°C). Snow is common in the Spring and Fall with regular accumulations of 12″ in a 24 hour period. At any time of year, be prepared for sudden changes. Unpredictability, more than anything else, characterizes Yellowstone’s weather. Always be equipped with a wide range of clothing options. Be sure to bring a warm jacket and rain gear even in the summer.
All vehicles and individuals entering the park must pay an entrance fee that is valid for seven days. The entrance fee provides entry to both Grand Teton National Park and Yellowstone National Park. Fees are $25 for non-commercial vehicles, $12 for hikers and cyclists, and $20 for motorcycles and snowmobiles. One year passes are available as an alternative to the seven day fee. The Park Annual Pass is $50 and provides entrance to Yellowstone and Grand Teton National Parks. The Interagency Annual Pass is $80 and provides entrance to most federal recreation sites across the country including Yellowstone and Grand Teton National Parks.
Yellowstone is one of the most popular national parks in the United States. Since the mid-1960s, at least 2 million tourists have visited the park almost every year. At peak summer levels, 3,700 employees work for Yellowstone National Park concessionaires. Concessionaires manage nine hotels and lodges, with a total of 2,238 hotel rooms and cabins available. They also oversee gas stations, stores and most of the campgrounds. Another 800 employees work either permanently or seasonally for the National Park Service.
Park service roads lead to major features; however, road reconstruction has produced temporary road closures. Yellowstone is in the midst of a long term road reconstruction effort, which is hampered by a short repair season. In the winter, all roads aside from the one which enters from Gardiner, Montana, and extends to Cooke City, Montana, are closed to wheeled vehicles.
Park roads are closed to wheeled vehicles from early November to mid April, but some park roads remain closed until mid-May. The park has 310 miles (499 km) of paved roads which can be accessed from 5 different entrances. There is no public transportation available inside the park, but several tour companies can be contacted for guided motorized transport. In the winter, concessionaires operate guided snowmobile and snow coach tours. Facilities in the Old Faithful, Canyon and Mammoth Hot Springs areas of the park are very busy during the summer months. Traffic jams created by road construction or by people observing wildlife can result in long delays.
The National Park Service maintains 9 visitor centers and museums and is responsible for maintenance of historical structures and many of the other 2,000 buildings. These structures include National Historical Landmarks such as the Old Faithful Inn built in 1903–04 and the entire Fort Yellowstone – Mammoth Hot Springs Historic District. A historical tour is available at Fort Yellowstone which details the history of the National Park Service and the development of the park. Campfire programs, guided walks and other interpretive presentations are available at numerous locations in the summer, and on a limited basis during other seasons.
Camping is available at a dozen campgrounds with more than 2,000 campsites. Camping is also available in surrounding National Forests, as well as in Grand Teton National Park to the south. Backcountry campsites are accessible only by foot or by horseback and require a permit. There are 1,100 miles (1,770 km) of hiking trails available. The park is not considered to be a good destination for mountaineering because of the instability of volcanic rock which predominates. Visitors with pets are required to keep them on a leash at all times and are limited to areas near roadways and in “frontcountry” zones such as drive in campgrounds. Around thermal features, wooden and paved trails have been constructed to ensure visitor safety, and most of these areas are handicapped accessible. The National Park Service maintains a year round clinic at Mammoth Hot Springs and provides emergency services throughout the year.
Hunting is not permitted, though it is in the surrounding National Forests in season. Fishing is a popular activity, and a Yellowstone Park fishing license is required to fish in park waters. Many park waters are fly fishing only and all native fish species are catch and release only. Boating is prohibited on rivers and creeks except for a 5 mile (8 km) stretch of the Lewis River between Lewis and Shoshone Lakes, and it is open to non-motorized use only. Yellowstone Lake has a marina, and the lake is the most popular boating destination.
In the early history of the park, visitors were allowed, and sometimes even encouraged, to feed the bears. The bears had learned to beg for food, and visitors welcomed the chance to get their pictures taken with them. This led to numerous injuries to humans each year.
In 1970, park officials changed their policy and started a vigorous program to educate the public on the dangers of close contact with bears, and to try to eliminate opportunities for bears to find food in campgrounds and trash collection areas. Although it has become more difficult to observe them in recent years, the number of human injuries and deaths has taken a significant drop and visitors are in less danger.
Other protected lands in the region include Caribou-Targhee, Gallatin, Custer, Shoshone and Bridger-Teton National Forests. The National Park Service’s John D. Rockefeller, Jr. Memorial Parkway is to the south and leads to Grand Teton National Park. The famed Beartooth Highway provides access from the northeast and has spectacular high altitude scenery. Nearby communities include West Yellowstone, Montana; Cody, Wyoming; Red Lodge, Montana; Ashton, Idaho; and Gardiner, Montana. The closest air transport is available by way of Bozeman; Billings, Montana; Jackson; Cody, Wyoming or Idaho Falls, Idaho. Salt Lake City, 320 miles (515 km) to the south, is the closest large metropolitan area.
Most visitors use private vehicles to get around inside Yellowstone National Park. There is no public transportation available within the park. Roads can become very crowded whenever people stop to view wildlife; use pullouts, and be respectful of other motorists to help avoid bear-jams. Cycling in the park can be a very rewarding experience, but due to the great distances in the park some additional planning to ensure that lodging is available each night. The park reserves a number of campsites for cyclists, but during the busy summer season it is probably best to reserve sites in advance wherever possible.
Yellowstone is world-famous for its natural heritage and beauty – and for the fact that it holds half the world’s geothermal features, with more than 10,000 examples. Travelers to Yellowstone can view more than 300 geysers (such as “Old Faithful”), pools of boiling mud, and an amazing assemblage of wildlife, such as grizzly bears, wolves, bison and elk, all while standing on the surface of the Earth’s largest known “super-volcano”.
Mammoth Hot Springs. Mineral-laden hot water flows from springs, depositing calcite and other substances in its wake. Over time, these deposits form large terraces and other shapes. Some of the terraces grow several inches per day. Fort Yellowstone. The historic center of activity during the United States Army’s tenure of the park. Bunsen Peak. The hike to the top of this 8,564 foot peak takes approximately three hours round trip. The peak overlooks the old Ft. Yellowstone area and it is only a gradual climb. Bring water and snacks (and bear bells if you think they’ll work).
Permits are required for all backcountry camping, and quotas are placed on the number of people that may use an area at a given time. The maximum stay per backcountry campsite varies from 1 to 3 nights per trip. Campfires are permitted only in established fire pits, and wood fires are not allowed in some backcountry campsites. A food storage pole is provided at most designated campsites so that food and attractants may be secured from bears. Neither hunting nor firearms are allowed in Yellowstone’s backcountry.
Though many of the animals in the park are used to seeing humans, the wildlife is nonetheless wild and should not be fed or disturbed. Stay at least 100 m away from bears and 25 m from all other wild animals! Bison, elk, moose, bears, and nearly all large animals can attack! For any doubters, the National Park Service has put a series of animal attack videos online these animals are large, wild, and potentially dangerous, so give them their space.
In addition, be aware that odors attract bears and other wildlife, so avoid carrying or cooking odorous foods and keep a clean camp; do not cook or store food in your tent. All food, garbage, or other odorous items used for preparing or cooking food must be secured from bears.
Treat all odorous products such as soap, deodorant, or other toiletries in the same manner as food. Do not leave packs containing food unattended, even for a few minutes. Animals which obtain human food often become aggressive and dependent on human foods, and many can suffer ill health or death from eating a non-native diet.
When camping, either filter, boil, or otherwise purify drinking water. Waters may be polluted by animal and/or human wastes, and intestinal infections from drinking untreated water are increasingly common.
Always stay on boardwalks in thermal areas. Scalding water underlies thin, breakable crusts; pools are near or above boiling temperatures. Every year visitors traveling off trail are seriously burned, and people have died from the scalding water. No swimming or bathing is allowed in thermal pools.
The weather can change rapidly and with little warning. A sunny, warm day can quickly become a cold, rainy or even snowy experience. Hypothermia can be a concern. Be prepared for a variety of weather conditions by bringing along appropriate clothing. Lightning can and does injure and kill people in the park, so watch the sky and take shelter in a building if you hear thunder.