Evidence suggest Native American inhabit the area now known as Wyoming, principally the Clovis, Folsom and Plano cultures.
1100– 1200 CE
Native peoples construct a medicine wheel in the Big Horn Mountains. It is 25 yards in diameter and features 28 spokes extending from the rim to the center.
Wyoming is claimed by France as part of Louisiana, which is named in honor of Louis XIV.
The Shoshone, Arapaho, Cheyenne, and Crow live in the eastern part of the region, hunting bison and living in tepees. The Ute people inhabit the western mountains and depend on gathering wild foods and hunting small game.
French explorer François de La Vérendrye enters Wyoming on an expedition to the Rocky Mountains.
With the Treaty of Fountainebleu, France cedes Louisiana to Spain. Spain returns the area to France in 1800 with the secretly struck Treaty of San Ildefonso.
1800–1849 WESTWARD EXPANSION
(December 30) The U.S. acquires portions of Wyoming (and 13 other future U.S. states) from France as part of the Louisiana Purchase. U.S. President Thomas Jefferson agrees to the purchase price of 78 million francs ($15,000,000) from French head of state Napoleon Bonaparte. The purchase is lauded by supporters and savaged by critics of Jefferson. It more than doubles the size of the United States and is a defining moment in the expansion of U.S. territory. The portion of Wyoming not included in the purchase remains part of Spanish-controlled New Spain.
After leaving the Lewis and Clark expedition, fur trader and explorer John Colter stumbles upon an area of Wyoming he names "Colter’s Hell" in his written reports. At the time, those who read these reports of thermal activity in the Yellowstone area consider them fictional.
Explorer Robert Stuart crosses the Great Continental Divide near South Pass and builds the first known cabin in Wyoming.
(June 4) Louisiana Territory is renamed Missouri Territory after the southern portion becomes the new state of Louisiana.
(October 20) The Treaty of 1818 establishes Oregon Country, which contains portions of western Wyoming, as shared territory between the U.S. and the United Kingdom.
(July 10) The Adams-Onís Treaty goes into effect, establishing a new border between the U.S. and New Spain. As a result, new portions of Wyoming are now claimed by Spain.
(August 10) Most of Wyoming becomes part of unorganized U.S. territory after the southeastern corner of Missouri Territory is admitted to the Union as the state of Missouri.
(September 27) New Spain achieves independence as Mexico, and Spanish-controlled areas of Wyoming are now part of the new country.
Fur trapper and explorer William Sublette discovers and names Independence Rock. A large granite rock approximately 130 feet high, it functions as a prominent and well-known landmark on the Oregon and Mormon migrant trails.
Fur traders William Sublette and Robert Campbell found the first business west of the Missouri River, Fort William, a rambling log stockade built at the confluence of the Laramie and North Platte Rivers. By 1836, it has become an important resting place and haven for trail-weary, Oregon-bound travelers. The 1849 California gold rush brings 50,000 emigrants through the fort.
Narcissa Prentiss Whitman and Eliza Hart Spalding make a marker at South Pass when they become the first European-American women to cross the U.S.
(March 2) Texas achieves independence from Mexico, and portions of Wyoming become disputed territory between Mexico and the newly formed Republic of Texas.
Captain John Fremont makes his first expedition to Wyoming, where he scales a 13,570-foot peak that is later named Fremont Peak in his honor.
(December 29) Texas becomes the 28th state admitted to the Union. The small part of Wyoming involved in Texas' territorial dispute with Mexico is included within the new state's boundaries.
(June 15) The Oregon Treaty ends U.S. boundary disputes with Great Britain, and the majority of Wyoming now becomes unorganized U.S. territory.
(February 2) The Treaty of Guadelupe Hildago ends the Mexican-American War. Mexico cedes land to the U.S. that includes portions of southwestern Wyoming.
(August 14) The U.S. organizes Oregon Territory, which includes portions of western Wyoming.
1850–1868 TERRITORIAL EVOLUTION
Mountain man and guide Jim Bridger locates what is now known as Bridger Pass. It is later used by the Union Pacific Railroad and eventually becomes Interstate 80.
(September 9) The Compromise of 1850 between Mexico and the U.S. results in portions of Wyoming becoming part of the newly formed Utah Territory.
The Fort Laramie Treaty is signed between the U.S. and the Sioux Native Americans. The Sioux pledge not to harass the wagon trains traveling the Oregon Trail in exchange for a $50,000 annuity. However, the treaty is soon broken by settlers continually trespassing onto Native American lands.
(May 30) The unorganized portion of Wyoming becomes part of Nebraska Territory. Wyoming is now split between Washington, Utah, and Nebraska territories.
(February 14) The western portion of Oregon Territory is admitted to the Union as the state of Oregon, and the region of Wyoming it encompassed becomes part of Washington Territory.
(February 28) The eastern tip of Washington Territory, correlating with the southwestern tip of present-day Wyoming, is transferred to Nebraska Territory.
(March 2) Dakota Territory, which encompasses northern Wyoming, is formed.
The Homestead Act attracts many new farmers and ranchers to Wyoming, where they congregate along fertile riverbanks.
John Bozeman and John Jacobs scout a direct route from Virginia City, Montana, to central Wyoming in order to join with the Oregon Trail. The trail passes directly through Native American territory occupied by the Shoshone, Arapaho, and Sioux nations. Violent encounters between settlers and Native Americans escalate.
(March 4) Idaho territory is created. It encompasses present-day Idaho, Montana, and most of Wyoming.
(August 29) The Battle of the Tongue Rover in Sheridan County becomes the major engagement of the Powder River Expedition, which destroys the Arapaho ability to raid the Bozeman Trail for some time. Sixty-three Arapaho are killed or wounded, and over 1,000 Arapaho-owned horses and ponies are destroyed.
Headed north to Montana, Nelson Story drives the first herd of cattle through Wyoming from Texas.
Gold is found near South Pass, leading to a gold rush and population boom in South Pass City.
Red Cloud’s War, a two-year war between the Sioux (led by Chief Red Cloud) and the U.S. Army, begins. The war is waged over control of Wyoming's Powder River Country, which is situated along a major access route to Montana's gold fields. The war ends with the signing of the Laramie Treaty, which closes the Bozeman Trail and three U.S. forts. The treaty also makes the Black Hills part of the Great Sioux Reservation.
(July 25) The Wyoming Territory is created. Its boundaries form the borders of the present-day state of Wyoming. Cheyenne is chosen as the territorial capital.
The Wind River Reservation for Shoshone Native Americans is created.
1869–1899 FROM TERRITORY TO STATEHOOD
(December 10) Wyoming's first territorial governor, John Allen Campbell, signs the "Female Suffrage" bill, making Wyoming the first territory to give women the right to vote. It also gives women the right to hold public office. When Wyoming is admitted to the Union, it becomes the first state with female suffrage, leading to its nickname, "The Equality State."
After R. S. Barr, resigns in protest of the passage of Wyoming's women's suffrage amendment, Esther Hobart Morris of South Pass City becomes the first woman to hold the position of Justice of the Peace in the United States and its territories.
William "Buffalo Bill" Cody begins guiding hunting parties through the Yellowstone and Big Horn Basin area. From 1868 to 1872, the famous cowboy is employed as a scout for the United States Army.
(March 1) President Ulysses S. Grant signs a measure creating the 2.2 million-acre Yellowstone National Park. Home to the famous "Old Faithful" geyser, the park is the first of its kind in the United States. The U.S. Army is commissioned to oversee it, but in 1917 park control is taken over by the National Park Service. In 2007, more than 3.1 million people visited Yellowstone.
(July 2) Colonel George Custer departs Fort Abraham Lincoln with 1,000 soldiers on a 1,200-mile expedition to chart the Black Hills of eastern Wyoming and western South Dakota.
The Black Hills War is fought along the border of Wyoming and Montana after miners continue to trespass into Native American lands. The famous Battle of the Little Bighorn leads to Colonel Custer’s death. In spring of 1877, Native Americans begin to surrender and are shipped to Indian Territory.
An agreement is made with the Shoshone Native Americans to allow the Arapahoe to move onto the Wind River Reservation.
After the U.S. government attempts to move the Nez Perce to a reservation in Idaho, Nez Perce Chief Joseph leads his people through the "Devil’s Doorway" in the Yellowstone area during their attempt to escape to Canada.
(September 2). Twenty-eight Chinese immigrant miners are killed and hundreds more are chased out of town by striking coal miners during the Chinese Massacre at Rock Springs. The massacre results from racial tensions and an ongoing labor dispute over the Union Pacific Coal Department’s policy of paying Chinese miners lower wages than white miners, leading Chinese laborers to be the preferred workers.
(July 10) Even though its population does not yet qualify it for statehood, Wyoming is admitted to the Union as the 44th state.
The Johnson County War, a battle between small settling ranchers and larger established ranches in the Powder River Country, is waged. It culminates in a lengthy shootout between local ranchers, a band of hired killers, and a sheriff’s posse. President Benjamin Harrison sends in the U.S. Cavalry to quell the violence.
(September 23) The first Frontier Days rodeo celebration in Cheyenne is held. By 1998, it has become the world’s largest outdoor rodeo.
1900–1949 EARLY TO MID 20TH CENTURY
(April 13) In Kemmerer, J.C. Penney opens his first store, selling clothes, shoes, and dry goods. By 1929 there are 1,395 J.C. Penney stores across the U.S.
(May 22) Encompassing 6,580,920 acres, the Yellowstone Forest Reserve becomes the first national forest in the country.
(September 24) President Theodore Roosevelt designates the Devil’s Tower National Monument in the Black Hills of Wyoming. The first U.S. National Monument, it is a volcanic rock formation rising 867 feet over a base of gray igneous rock.
Uranium is discovered near Lusk. Wyoming still has the largest known uranium ore reserve in the U.S.
(January 27) Wyoming becomes the 27th state to ratify the 19th Amendment, granting women nationwide the right to vote.
(April 15) Wyoming Senator John Kendrick introduces a resolution that sets into motion one of the most significant investigations in Senate history, Teapot Dome. The Teapot Dome scandal involves a secret arrangement by Secretary of the Interior Albert B. Fall to lease the U.S. naval petroleum reserve at Wyoming’s Teapot Dome to a private oil company without competitive bidding. The case results in the conviction and imprisonment Fall. The oil fields are returned to the federal government in 1927 by Supreme Court ruling.
Wyoming's Nellie Taylor Ross is elected the nation’s first woman governor. Ross serves out the remaining term of her husband William Ross, who died in office. From 1933 to 1935, she would serve as the female woman director of the U.S. Mint.
Grand Teton National Park is established in northwestern Wyoming. The park is named after the Grand Teton, which at 13,770 feet is the tallest mountain in the Teton Range.
A massive infestation of crickets in Montana and Wyoming causes nearly $1 million in crop damage.
After the Japanese bomb Pearl Harbor, many people of Japanese descent living on the Pacific Coast are relocated to the Heart Mountain Relocation Center in Wyoming. The location for the center is chosen because it is remote yet convenient, adjacent to a railroad depot where internees could be unloaded and processed.
1950–PRESENT MODERN WYOMING
More than one million acres of Yellowstone National Park burns. Ignited by lightning, the fires last from May to September.
Wyoming leads the country in coal production with 3 million tons produced per week.
Wolves are returned to Yellowstone National Park where they thrive. The last grey wolf had disappeared from the Yellowstone region in 1926. By 2008 their population reaches 1,500.
(October 7) In Laramie 22-year old University of Wyoming student Matthew Shepard, who is gay, is found beaten, burned, and tied to a wooden ranch fence. Shepard dies from his injuries on October 12. Two men, Russell Arthur Henderson and Aaron James McKinney, are tried for the murder, which many attribute to Shepard's sexual orientation. Both men receive multiple life sentences. The incident garners nationwide attention and spurs calls for changes to national hate crime legislation.
(February 1) In a case that goes straight to the U.S. Supreme Court, Montana sues Wyoming over provisions of the 1950 Yellowstone River Compact. The Montana government insists its neighbor takes more Tongue and Powder rivers water than it is entitled to, cheating Montana out of its share. The case is still pending.
The Matthew Shepard Act, which extends hate crime legislation to cover violent crimes committed for reasons of the victim's gender, sexual orientation, gender identity, or disability, passes in the Senate by a vote of 68-29. President Barack Obama signs the legislation into law on October 28.
Click to enlarge an image
1200: Medicine Wheel National Historic Landmark
1682: Louis XIV
1700: Modern-day Southern Arapaho women's leggings and moccasins
1807: John Colter historical marker
1812: North American continental divides
1836: Narcissa Whitman
1842: Illustration of John Fremont
1850: Jim Bridger
1863: John Bozeman
1865: Map of the Bozeman Trail (in yellow)
1866: Red Cloud
1869: John Allen Campbell
1871: William "Buffalo Bill" Cody
1872: Old Faithful
1874: Colonel George Custer
1876: A Battle of Little Bighorn battlefield marker
1885: Rock Springs Massacre
1892: Johnson County War map
1906: Devil’s Tower National Monument
1922: Postcard of Teapot Rock on Teapot Dome
1924: Nellie Tayloe Ross, 14th Governor of Wyoming
1929: Grand Teton in winter
2009: President Barack Obama signs the Matthew Shepard Act into law.