80,000,000- 60,000,000 B.C. - Dinosaurs die off in Montana.
2,000,000-20,000 B.C. - Series of glacial ice sheets cover portions of Montana.
15,000-13,000 B.C. - Asiatic people migrate over land bridge to Montana.
8,000-6,500 B.C. - Prehistoric people develop communal hunting techniques in Montana.
6,500 B.C.-1,500 A.D. - Prehistoric people populate all areas of Montana.
1680 - Montana natives acquire the horse.
1720 - Montana natives acquire the gun.
1803 - United States acquires most of Montana in the Louisiana Purchase
1805-1806 - Lewis and Clark Expedition crosses and recrosses Montana
1807 - Manuel Lisa builds first fur fort in Montana on the Yellowstone River
1828 - Fort Union, an American Fur Company post, is built at the mouth of the Yellowstone River
1841 - Father Pierre Jean de Smer establishes St. Mary's Mission in the Bitterrot Valley
1846 - The Oregon Treaty gives the rest of Montana to the U.S.
1847 - Fort Benton founded on Missouri River as military and trading post; soon becoming world-renown "Head of Navigation" to the west, and world's furthest inland port. Steamboats brought gold seekers, fur traders, settlers and supplies, making Fort Benton the "Birthplace of Montana."
1853 - Johnny Grant starts the first beef herd in the Deer Lodge Valley
1857 - First sheep ranching begins in the Bitterroot Valley
1860 - First steamboat reaches Fort Benton
Placer miners rush to gold strike on Grasshopper Creek (Bannack)
14 July, James Stuart becomes first lawman in Montana History, elected sheriff of Gold Creek with jurisdiction covering most of Western Montana. Served to April 1863.
May, Crawford resigns and returns home to an eastern state. Outlaw gang leader Henry Plummer elected sheriff of Bannack and all gold camps southeast of the Bitterroot.
29 June, Chief Deputy Donald H, Dillingham of Virginia City, becomes first lawman killed in the Line of Duty, assassinated in broad-daylight on Virginia City's Main Street by two of Plummer's deputies.
December, 102 known killed and over a quarter million dollars in gold (at 1863 prices) stolen by Plummer's "Road Agents" gang. Outraged citizens form Vigilante Committee, and within five weeks 21 gang members hung, countless others banished from Territory.
Vigilantes hang Henry Plummer and other "Innocents";
26 May, Montana Territory officially created by act of President Abraham Lincoln, Bannack chosen as first Territorial Capitol.
First newspaper, the Montana Post, published in Virginia City
1865 - Montana's first U.S. Marshal appointed by President Lincoln: George M. Pinney, serving from 1865 to 1867. Pinney first sets up his office in Butte, later moving to Helena.
1866 - U.S. Military Post, Camp Cooke, created on the Judith River.
1870 - Open-range cattle industry begins on Montana Prairies
1872 - Congress creates Yellowstone National Park
1873 - Beginning of Royal Canadian Mounted Police, to "destroy illegal whiskey trade and lawlessness" caused by the "Whoop-Up Trail" operation from Fort Benton into Canadian Northwest Territories, the "Trail" having been created by Fort Benton's first sheriff, and subsequently participated in and protected by five of his successors.
24 June, Sioux Indians defeat Col. George ArmB Custer and 7th Cavalry at Battle of Little Big Horn River.
Following, Nez Pierce Indian Chief Joseph leads his people out of Oregon into Montana, outwitting superior U.S. Army forces, until surrender in 1877 near Bear's Paw Mountains in northern Montana.
Significant copper mining begins in Butte;
Chief Joseph and the Nez Perce retreat across Montana
1880 - Utah and Northern Railroad enters Montana
Northern Pacific Railroad is completed through Montana;
Marcus Daly establishes the town of Anaconda and its smelting works
1885 - Montana Territorial Government creates first "state" law enforcement agency: Montana Department of Livestock.
1889 - 08 November, Montana becomes 41st state of United States under President Benjamin Harrison's administration, 16 original counties established, and 16 sheriffs appointed by new state government.
1890 - First hydroelectric dam is built at Great Falls
1902 - Montana Capitol Building is completed.
1903 - Amalgamated Copper Company paralyzes the state's economy with the shut-down to force legislative relief.
1909 -Chicago, Milwaukee, St. Paul and Pacific Railroad ("Milwaukee Road") is completed through Montana.
Congress establishes Glacier National Park;
forest fires devastate western Montana.
1910-1918 - Homesteading boom peaks on Montana's plains.
1911-1925 - "County-busting" craze creates 25 new Montana counties.
1914 - Montana women receive the franchise (right to vote).
1916 - Jeanette Rankin elected the first woman in the U.S. Congress.
Rankin votes against U.S. entry into World War I;
Industrial Workers of the World (IWW) organizer Frank Little is lynched in Butte.
1918 - February, Mrs Leo Hunter, Rosebud County Sheriff's Office, appointed first female law officer in state.
1919 - First of severe agricultural depressions (extending into the early 1940s) begins in Montana; oil is discovered in the Cat Creek field.
1921 - Wave of bank failures begins in Montana.
1922 - KDYS (Great Falls), Montana's first licensed radio station, broadcasts.
1923 - Jack Dempsey-Tommy Gibbons world heavyweight championship fight is staged in Shelby.
1926 - Montana artist Charlie Russell dies in Great Falls.
1930 - Significant tourist industry begins in Montana.
Construction of Fort Peck Dam begins;
scores of Civilian Conservation Corps (CCC) camps are established across Montana.
Works Progress Administration (WPA) begins projects in Montana;
Series of severe earthquakes hits central Montana
1936 - Rural Electrification Administration (REA) begins work in Montana
1941 - Congresswoman Jeanette Rankin votes against U.S. entry into World War II
1943 - Smith Mine disaster kills 70 coal miners
1950 - Great Falls replaces Butte as Montana's largest city
1951 - Petroleum boom begins in eastern Montana
1952 - Mike Mansfield is first elected to the U.S. Senate
1953 - KOOK-TV (Billings), Montana's first licensed television state, broadcasts
Aluminum plant begins processing in Columbia Falls;
Berkeley Pit copper operation starts in Butte
1956 - Construction of the federal interstate-highway system begins in Montana
1959 - Severe earthquakes hit upper Madison Valley
1961 - Malmstrom Air Force Base (Great Falls) becomes site of the nation's first ICBM missile command
1964 - Congress passes federal Wilderness Act
Bell Creek petroleum field is discovered and developed;
Longest and costliest strike in Montana history runs in Butte
1968 - Yellowtail Dam is completed; Work begins on Libby Dam
1969 - Large-scale strip mining of coal begins at Colstrip
1970 - Consolidation creates the Burlington Northern Railroad
1972 - Montana's electorate approves new constitution
1975 - Underground mining ceases in Butte
1976 - Mike Mansfield retires from U.S. Senate; becomes U.S. ambassador to Japan
Anaconda Company announces the closing of its Montana operations;
Billings replaces Great Falls as Montana's largest city;
Fallout from Mount St. Helena volcanic eruption blankets Montana
1981 - Milwaukee Road declares bankruptcy
1982 - Copper-mining operations cease at Butte's Berkeley Pit
Limited underground mining resumes in Butte;
Some high-tech gold mining reopens in Montana mountains
Burlington Northern sells a major portion of its Montana trackage to Montana Rail Link;
Last gaps in federal interstate-highway system are completed in Montana
U.S. and Canada initiate a Free-Trade Agreement, directly affecting Montana's economy;
Large forest fires sweep areas of a drought-striken MOntana and Yellowstone National Park
1989 - Montana celebrates its statehood centennial
1990 - Montana's timber-industry income declines, while gains occur in tourism and specialized mining
1991 - Riot at State Prison in Deer Lodge results in five deaths.
As a result of the 1990 federal census, Montana loses one of its two representatives in Congress; two incumbents oppose each other for the remaining seat;
Attorney General Marc Racicot (R) defeats legislator Dorothy Bradley (D) for governor's seat.
Robert Redford's film, "A River Runs Through It," sparks increased tourism and immigration to Montana;
a generally wet summer produces record agricultural harvests.
1994 - 4,500 wildfires rage across Montana, burning 286,000 acres.
1995 - Wolves are returned to Yellowstone National Park, where they thrive.
Montana Freeman and federal agents involved in a standoff in eastern Montana;
"Unabomber" Ted Kaczynski captured near Lincoln.
1997 - A prison-population overflow creates a housing crisis for inmates, some sent out-of-state.
1998 - The Montana Power Company sells its electric generating facilities to Pacific Power and Light, Global, Inc.
1999 - As highway deaths rise, Montana reinstitutes a daylight speed limit of 70 mph on 2-lane paved roads.
Summer wildfires scorch nearly 1,000,000 acres and raze 320 homes, mostly in the Bitterroot Valley;
19,600,000 acres of state and federal land are closed due to fire hazard.
The Montana Legislature deregulates the electric industry in the state;
wildfires again dominate Montana's drought-beset summer.