12,000 B.C. First inhabitants of Colorado include Folsom Man.
3000 B.C. Prehistoric farming communities appear.
A.D. 1000 Ancestral Puebloan cliff-dweller culture peaks in Four Corners region.
Late 1500s Spanish explore upper Rio Grande Valley; colonize Santa Fe and Taos, New Mexico; and make forays into what is now southern Colorado.
1776 U.S. declares independence from England.
1803 The Louisiana Purchase includes most of modern Colorado.
1805 The Lewis and Clark expedition sights the Rocky Mountains.
1806-07 Capt. Zebulon Pike leads first U.S. expedition into the Colorado Rockies.
1822 William Becknell establishes the Santa Fe Trail.
1842-44 Lieut. John C. Frémont and Kit Carson explore Colorado and the American West.
1848 Treaty of Guadalupe-Hidalgo ends the Mexican War, adds American Southwest to the United States.
1858 Gold discovered in modern Denver.
1859 Gen. William Larimer founds Denver. Major gold strikes in nearby Rockies.
1861 Colorado Territory proclaimed.
1862 Colorado cavalry wins major Civil War battle at Glorieta Pass, New Mexico. The Homestead Act is passed.
1863-68 Ute tribe obtains treaties guaranteeing 16 million acres of western Colorado land.
1864 Hundreds of Cheyenne and Arapaho killed in Sand Creek Massacre. The University of Denver becomes Colorado's first institution of higher education.
1871 Gen. William Palmer founds Colorado Springs.
1876 Colorado becomes 38th state.
1877 University of Colorado opens in Boulder.
1878 Little Pittsburg silver strike launches Leadville's mining boom, Colorado's greatest.
1879 Milk Creek Massacre by Ute warriors leads to tribe's removal to reservations.
1890 Sherman Silver Purchase Act boosts price of silver. Gold discovered at Cripple Creek, leading to state's biggest gold rush.
1893 Women win right to vote. Silver industry collapses following repeal of Sherman Silver Purchase Act.
1901-07 President Theodore Roosevelt sets aside 16 million acres of national forestland in Colorado.
1906 U.S. Mint built in Denver.
1913 Wolf Creek Pass is first highway to cross Continental Divide in Colorado.
1915 Rocky Mountain National Park established.
1934 Direct Denver-San Francisco rail travel begins. Taylor Grazing Act ends homesteading.
1941-45 World War II establishes Colorado as a military center.
1947 Aspen's first chairlift begins operation.
1948-58 Uranium "rush" sweeps western slope.
1955 Environmentalists prevent construction of Echo Park Dam in Dinosaur National Monument.
1967 Colorado legalizes medically necessary abortions.
1972 Colorado voters reject a chance to host the 1976 Winter Olympics.
1988 Sen. Gary Hart, a front-runner for the Democratic presidential nomination, withdraws from the race after a scandal involving a Miami model.
1992 Colorado voters approve Amendment 2, a controversial state constitutional amendment barring any measures to protect homosexuals from discrimination.
1995 The $4.2-billion state-of-the-art Denver International Airport and $2.16-million Coors Field baseball stadium open. Denver goes sports-crazy with its fourth major professional sports team, the Avalanche, a member of the National Hockey League.
1996 The U.S. Supreme Court strikes down Amendment 2, saying it denies gays and lesbians constitutional rights afforded to all Americans. The Avalanche win the Stanley Cup, giving Colorado its first championship in any major league.
1997 Weather wreaks havoc across the state: First, a summer rainstorm turns a small creek that runs through Fort Collins into a roaring river that floods parts of the town, killing five residents and causing some $200 million in damage; then, in late October, a 24-hour blizzard, the worst October storm in Denver since 1923, piles snow across the Front Range, virtually shutting down I-25 from Wyoming to New Mexico and stranding thousands of passengers at Denver International Airport. Gary Lee Davis, convicted of the 1986 abduction and murder of a Colorado farm wife, is executed by lethal injection, the state's first execution in 30 years.
1998 The Denver Broncos win the Super Bowl, defeating the Green Bay Packers (the defending champs) 31-24; the stunning victory saves the Broncos the indignity of becoming the first team to lose five Super Bowls. Militant environmental activists set fires that cause more than $12 million in damage in an effort to stop expansion at a Vail resort.
1999 The Broncos win the Super Bowl again, this time defeating the Atlanta Falcons. The worst school shooting in United States history takes place in suburban Denver when two students open fire inside Columbine High School, killing 13.
2000 Colorado ski resorts report that the 1999-2000 season was the worst in history due to poor snowfall and potential skiers' fears about Y2K problems.
2001 The Avalanche win the Stanley Cup again, beating the New Jersey Devils 3-1. A California couple give the University of Colorado $250 million, the largest gift ever to a public university in the United States.
2001-08 A new energy boom takes place in Colorado, with drilling for oil and gas hitting an all-time high.
2002 One of the worst wildfire seasons in history hits Colorado, with about 1,000 fires burning some 364,000 acres across the state; the biggest fire -- considered the largest forest fire in the state's history -- burned 138,000 acres and destroyed 133 homes southwest of Denver; other major fires were near Durango, in Mesa Verde National Park, near Colorado Springs, and near Glenwood Springs.
2003 Scandal hits the U.S. Air Force Academy in Colorado Springs when dozens of female cadets come forward claiming that they had been victims of sexual assaults by male cadets and that academy officials had mostly ignored their complaints and sometimes blamed the victims.
2004 Colorado obtains its fourth national park when Great Sand Dunes gains national park status, after getting additional land with help from the Nature Conservancy.
2006 T-REX, the biggest road and light-rail project in Denver history, is completed.
2006-07 Thanks to plenty of snow, Colorado's ski industry enjoys a record year: over 12.5 million visitors, nearly a quarter of the nation's total.
2008 Denver hosts the 2008 Democratic National Convention.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.