History of Yellowstone National Park in Timeline

Yellowstone National Park, primarily in Wyoming with small portions in Montana and Idaho, was established on March 1, 1872, by President Ulysses S. Grant, making it the first national park in the United States and widely considered the first in the world. Renowned for its diverse wildlife and geothermal activity, its most famous attraction is the Old Faithful geyser. The park's dominant biome is the subalpine forest, and it is part of the South Central Rockies forests ecoregion.

1900: Lacey Act

In 1900, the Lacey Act provided legal support for officials prosecuting poachers in Yellowstone, aiding in the protection of the park's wildlife.

1901: Chicago, Burlington & Quincy Connection

In 1901, a Chicago, Burlington & Quincy connection opened via Cody, facilitating increased visitation to Yellowstone.

1902: Railroad Expansion

In 1902, the Northern Pacific Railroad extended its spur line to Gardiner station, allowing passengers to switch to stagecoaches for further travel into Yellowstone.

1902: Bison population decline

In 1902, the bison population in Yellowstone National Park had decreased to less than 50 individuals.

1903: Old Faithful Inn Construction

The Old Faithful Inn construction began in 1903.

1904: Old Faithful Inn Construction

The Old Faithful Inn was built from 1903 to 1904.

1908: Union Pacific Railroad Connection

In 1908, a Union Pacific Railroad connection to West Yellowstone was established, further improving access for visitors to the park.

1910: Visitor interaction with bears

Starting in 1910, black bears became a park symbol in Yellowstone National Park due to visitor interaction with the bears.

1914: U.S. Congress appropriates funds for animal extermination

Starting in 1914, the U.S. Congress appropriated funds to be used for "destroying wolves, prairie dogs, and other animals injurious to agriculture and animal husbandry" on public lands including Yellowstone National Park.

1915: Automobile Increase

By 1915, the increasing number of automobiles entering Yellowstone, reaching 1,000 per year, led to conflicts with horse-drawn transportation, eventually resulting in the prohibition of horse travel on roads.

1916: National Park Service Creation

In 1916, the National Park Service was created, and many of the management principles developed by the U.S. Army in Yellowstone were adopted by the new agency.

1916: U.S. Army Management

In 1916, the U.S. Army's management of Yellowstone ended after 30 years, with many of their management principles being adopted by the newly created National Park Service.

1917: Administration to National Park Service

In 1917, the administration of Yellowstone National Park was transferred to the National Park Service, which had been created the previous year.

October 31, 1918: Army Transfers Control

On October 31, 1918, the U.S. Army turned over control of Yellowstone National Park to the National Park Service, ending their 22-year oversight.

1918: Previous Yellowstone River Height Record

In June 2022, the Yellowstone River rose to a new record height at 13.88 feet (4.23 m), breaking a previous record of 11.5 feet (3.5 m) set in 1918.

1921: Mammoth School Opens

In 1921, the Mammoth School, created by the Park Service, opened.

1926: Wolves killed by Park Service hunters

By 1926, Park Service hunters had killed 136 wolves in Yellowstone National Park as part of an extermination program.

1927: Milwaukee Road Connection

In 1927, a Milwaukee Road connection to Gallatin Gateway near Bozeman opened, motorcoaching visitors via West Yellowstone.

1933: Coldest Temperature Recorded

In 1933, Yellowstone recorded its coldest temperature at −66 °F (−54 °C).

1933: CCC Involvement Begins

In 1933, the Civilian Conservation Corps (CCC) began playing a major role in developing Yellowstone's facilities through reforestation, campground and trail development, fire hazard reduction, and firefighting work.

1935: National Park Service ends extermination practice

In 1935, the National Park Service ended the practice of exterminating wolves and other animals in Yellowstone National Park.

1942: End of CCC Projects

By 1942, the Civilian Conservation Corps (CCC) completed the majority of early visitor centers, campgrounds, and the current system of park roads in Yellowstone.

1959: Hebgen Lake Earthquake

In 1959, the 7.2‑magnitude Hebgen Lake earthquake occurred just outside the northwest boundary of Yellowstone Park, triggering a landslide and subsequent dam collapse on Hebgen Lake, forming Earthquake Lake.

1963: Leopold Report

In 1963, following public controversy regarding elk population management, United States Secretary of the Interior Stewart Udall appointed an advisory board to collect scientific data, which resulted in the Leopold Report recommending management of Yellowstone's elk population.

1966: Mission 66 Planned Completion

By 1966, Mission 66, an effort to modernize and expand park service facilities to accommodate increased visitation, was planned to be completed in honor of the 50th anniversary of the National Park Service.

1970: Policy Change Regarding Bears

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 in Yellowstone National Park.

1973: Endangered Species Act passed

With the passing of the Endangered Species Act in 1973, the wolf was one of the first mammal species listed.

June 30, 1975: 6.1-magnitude earthquake inside the park

On June 30, 1975, a 6.1‑magnitude earthquake struck inside Yellowstone National Park, causing minimal damage.

July 28, 1975: Grizzly listed as a threatened species

On July 28, 1975, the grizzly bear was initially listed as a threatened species in the contiguous United States by the Fish and Wildlife Service.

October 26, 1976: International Biosphere Reserve

On October 26, 1976, Yellowstone was designated an International Biosphere Reserve.

September 8, 1978: UN World Heritage Site Designation

On September 8, 1978, Yellowstone was designated as a UN World Heritage Site, recognizing its natural and cultural significance.

1978: UNESCO World Heritage Site

In 1978, Yellowstone National Park was named a UNESCO World Heritage Site, recognizing its outstanding universal value.

February 22, 1980: Largest earthquake since February 22, 1980

On March 30, 2014, a magnitude 4.8 earthquake struck almost the very middle of Yellowstone near the Norris Basin; reports indicated no damage. This was the largest earthquake to hit the park since February 22, 1980.

1980: Mount St. Helens eruption

The 1980 eruption of Mount St. Helens was mentioned as a comparison point to the scale of eruptions associated with the Yellowstone Caldera.

1983: Earthquake swarms

From 1983 to 2008 there were 70 swarms of earthquakes, showcasing how common these events were within Yellowstone National Park.

1985: Earthquake swarm detected

For three months in 1985, 3,000 minor earthquakes were detected in the northwestern section of Yellowstone park during an earthquake swarm, attributed to minor subsidence of the Yellowstone caldera.

July 21, 1987: Teton-Yellowstone Tornado

On July 21, 1987, the most powerful tornado recorded in Wyoming, the Teton–Yellowstone tornado, touched down in the Teton Wilderness and hit Yellowstone National Park, classified as an F4 with wind speeds estimated at between 207 and 260 miles per hour.

August 20, 1988: Black Saturday

On August 20, 1988, known as "Black Saturday", strong winds rapidly expanded the Yellowstone fires, resulting in more than 150,000 acres burned.

1988: Forest Fires

In 1988, Yellowstone experienced large forest fires that burned nearly one-third of the park, leading to a re-evaluation of fire management policies.

1988: Grant Village Damage

In 1988, the enormous forest fires damaged much of Grant Village, leading to the rebuilding of structures in the traditional log cabin style.

1992: New Fire Management Plan Adopted

In 1992, Yellowstone adopted a new fire management plan with stricter guidelines for the management of natural fires, based on the knowledge gained from the 1988 fires.

1995: List of World Heritage in Danger

In 1995, Yellowstone was placed on the List of World Heritage in Danger due to the effects of tourism, infection of wildlife, and issues with invasive species.

1995: Wolves reintroduced to Yellowstone

In 1995, the reintroduction of northwestern wolves imported from Canada, began in Yellowstone National Park.

1996: Bison corralled back into the park

During the winter of 1996–1997, national park personnel regularly corral bison herds back into Yellowstone National Park when they venture outside of the area's borders to combat the threat of brucellosis transmission to cattle.

1996: Previous Lamar River Height Record

In June 2022, flooding on the Lamar River reached 16.7 feet (5.1 m), beating a 1996 record of 12.15 feet (3.70 m).

1997: Slaughter of bison

During the winter of 1996–1997, 1,079 bison that had exited Yellowstone National Park were either shot or sent to slaughter.

1998: Last sighting of Lynx

Lynx have not been seen in Yellowstone National Park since 1998.

1999: Nesting bald eagles documented

In 1999, twenty-six pairs of nesting bald eagles were documented in Yellowstone National Park.

May 2001: Yellowstone Volcano Observatory Created

In May 2001, the U.S. Geological Survey, Yellowstone National Park, and the University of Utah created the Yellowstone Volcano Observatory (YVO) to monitor geological processes and potential hazards in the Yellowstone Plateau volcanic field.

2001: DNA from hair samples confirms Lynx presence

In 2001, DNA taken from hair samples confirmed that lynx were at least transient to Yellowstone National Park.

2001: Catch and release regulations

Since 2001, all native sport fish species caught in Yellowstone National Park waterways are subject to catch and release regulations.

2002: Record High Temperature

In 2002, Yellowstone recorded its highest temperature at 99 °F (37 °C).

2003: Bison population increase

By 2003, the bison population in Yellowstone National Park had increased to 4,000.

2003: Removed from Danger List

In 2003, Yellowstone was removed from the List of World Heritage in Danger.

2003: Norris Geyser Basin Changes

In 2003, changes at the Norris Geyser Basin resulted in trail closures due to new fumaroles, enhanced geyser activity, and increasing water temperatures.

2003: Lynx tracks spotted and followed

In 2003, the tracks of one female lynx and her cub were spotted and followed for over 2 miles in Yellowstone. Fecal material and other evidence obtained were tested and confirmed to be those of a lynx.

March 10, 2004: Bison deaths due to toxic geothermal gases

On March 10, 2004, a biologist discovered 5 dead bison which apparently had inhaled toxic geothermal gases trapped in the Norris Geyser Basin by a seasonal atmospheric inversion.

April 2004: Upsurge in earthquake activity

In April 2004, following the discovery of dead bison, there was an upsurge in earthquake activity in Yellowstone National Park.

2004: Wolf Pack Survey

In 2004, a survey of wolf packs was conducted in Yellowstone National Park. The population number declined from 2004 to 2005, but it may be attributable to wolf migration to other nearby areas.

2005: Wolf survey

A survey conducted in 2005 reported that there were 13 wolf packs, totaling 118 individuals in Yellowstone National Park.

2005: Discovery of molecular hydrogen sustenance for hyperthermophilic species

In 2005, researchers from the University of Colorado at Boulder discovered that the sustenance for at least some of the diverse hyperthermophilic species in Yellowstone's hot waters is molecular hydrogen.

2005: Peak bison population

In 2005, the Yellowstone Park bison herd reached a peak with 4,900 animals.

2006: Ground movement increase in Mallard Lake Dome and Sour Creek Dome

In 2006, it was reported that the Mallard Lake Dome and the Sour Creek Dome had risen at a rate of 1.5 to 2.4 inches (3.8 to 6.1 cm) per year from mid–2004 through 2006.

2006: Canyon Village Visitor Center Opens

In 2006, the visitor center at Canyon Village opened, incorporating a more traditional design.

April 30, 2007: Earthquake swarm in Yellowstone Caldera

Beginning on April 30, 2007, 16 small earthquakes with magnitudes up to 2.7 occurred in the Yellowstone Caldera over several days.

2007: Whitebark pine threatened by fungus

As of 2007, the whitebark pine in Yellowstone National Park is threatened by a fungus known as white pine blister rust.

2007: Uplift continues at a reduced rate

As of late 2007, the uplift in the Mallard Lake Dome and the Sour Creek Dome areas has continued, albeit at a reduced rate.

2007: Average Annual Visitation

From 2007 to 2016, the average annual visitation to Yellowstone National Park increased to 3.5 million.

2007: Recorded Deaths

From 2007 to 2023, a total of 74 deaths were recorded within Yellowstone National Park.

2007: Grizzly bear delisting

In 2007, the grizzly bear was taken off the endangered species list in Yellowstone National Park.

2007: Summer estimated population of bison

In 2007, the summer estimated population of bison was 4,700 in Yellowstone National Park.

February 27, 2008: Northern Rocky Mountain wolf population removed from endangered species list

On February 27, 2008, the U.S. Fish and Wildlife Service removed the Northern Rocky Mountain wolf population from the endangered species list.

December 2008: Earthquake swarm under Yellowstone Lake

In December 2008, over 250 earthquakes were measured over four days under Yellowstone Lake, the largest measuring a magnitude of 3.9.

2008: Mammoth School Closes

In 2008, the Mammoth School closed due to fewer employees with dependent children and an interstate agreement to send Wyoming money to Montana.

2008: Decline in bison population after harsh winter

In 2008, the number of bison in Yellowstone National Park dropped to 3,000 after a harsh winter and controversial brucellosis management strategies.

2009: Grizzly bear delisting overturned

In 2009, a federal district judge overturned the delisting ruling, reinstating the grizzly bear as a threatened species in Yellowstone National Park.

January 2010: Earthquake swarm detected

In January 2010, more than 250 earthquakes were detected over two days within Yellowstone National Park.

2010: America the Beautiful Quarters Program

In 2010, Yellowstone National Park was honored with its own quarter under the America the Beautiful Quarters Program.

2011: Geyser Study

In 2011, a study found that at least 1,283 geysers have erupted in Yellowstone, with an average of 465 active in a given year.

October 1, 2013: Park Closure

On October 1, 2013, Yellowstone National Park closed due to the 2013 United States federal government shutdown.

March 30, 2014: Magnitude 4.8 earthquake strikes near Norris Basin

On March 30, 2014, a magnitude 4.8 earthquake struck near the Norris Basin in Yellowstone National Park. Reports indicated no damage.

2014: Fire Management Plan

In 2014, the latest Fire Management Plan was implemented, allowing natural fires to burn if they posed no immediate threat to lives and property.

August 2015: Bear-Related Death

In August 2015, the eighth recorded bear-related death in the park's history occurred in Yellowstone National Park.

2016: Record Recreational Visitors

In 2016, Yellowstone National Park had a record of 4,257,177 recreational visitors.

2016: Discovery of Hadesarchaea

In 2016, researchers from Uppsala University reported the discovery of a class of thermophiles, Hadesarchaea, in Yellowstone's Culex Basin.

2017: Grizzly bears living in the Greater Yellowstone Ecosystem

As of 2017, an estimated 700 grizzly bears were living in the Greater Yellowstone Ecosystem, with about 150 grizzlies living wholly or partially within Yellowstone National Park. The grizzly bear was removed from the endangered species list in 2017.

September 2018: Restoration of grizzly bear protections

In September 2018, a U.S. district judge ruled that the grizzly's protections must be restored in full, arguing the Fish and Wildlife Service was mistaken in removing the bear from the threatened status list in Yellowstone National Park.

2021: Suspension of Programs due to COVID-19

In 2021, campfire programs, guided walks, and other interpretive presentations were suspended in Yellowstone National Park due to COVID-19.

June 2022: Park Closure and Evacuation

In June 2022, Yellowstone National Park experienced record-level rainfall and flooding causing the park to close entrances and evacuate visitors. The Yellowstone River rose to a record height of 13.88 feet (4.23 m), resulting in road and bridge failures, power outages, and mudslides.

2022: School Options for Park Employees

As of 2022, resident park employees living in the Mammoth, Wyoming area may send their children to school in Gardiner Public Schools of Gardiner, Montana.