August 3, 1900
Colorado State Home and Industrial School for Girls, established by statute in 1887 for wayward girls ages 6 to 18, moves to Morrison in Jefferson County. The name was changed to Mount View Girl's School in 1961.
- Edgewater is incorporated
- Alferd Packer, recently paroled, works as a ranch hand on the Rooney Ranch
- Coors Brewery wins international brewing award in Prague (now capital of the Czech Republic)
- Table Mountain Resort in Golden opens with bowling and evening dance
- Denver Interurban electric streetcar begins service to Arvada from downtown Denver
- Coal mining company town of Leyden established
- Colorado National Guard’s Rifle Range established, renamed Camp George West in 1934
- George West family form the Transcript Printing Company - a family corporation
Jewish Consumptive Relief Society (JCRS) founded in Lakewood as a non-sectarian sanatorium to treat tuberculosis patients in all stages of the disease. Patients come from all over North America and are admitted free of charge. The Sanatorium is headed by Dr. Charles Spivak and Phillip Hillkowitz.
October 11, 1904
Town of Mountain View, or "Mount View," incorporated.
- Cheesman Dam on South Platte River, world’s tallest dam at 221 feet tall, completed
- Golden Illuminating Company installs streetlights in Golden, the first incandescent street lamps in the state
August 9, 1905
Evangelical Lutheran Sanitorium established as a tent colony for tuberculosis patients in Wheat Ridge, later becomes Lutheran Hospital.
January 29, 1906
Town of Morrison incorporated.
May 31, 1906
Earliest documented performance at Red Rocks Amphitheatre when “Grand Opening of the Garden of the Titans” takes place.
November 15, 1906
George West, publisher of the Colorado Transcript newspaper, dies.
Death of alleged Colorado cannibal Alferd Packer, a resident of Deer Creek after his release from prison in 1901.
January 8, 1907
Wildfire destroys Wilson Ranch and threatens town of Leyden.
April 9, 1907
Thirty square mile extreme southern tip of Jefferson County transferred to Park County.
November 12, 1907
Small town of Lakeside incorporated.
- Crown Hill Cemetery established. Tower of Memories built in 1926-1948.
- Harrisburg changes its name to Westminster.
May 15, 1908
"M" emblem for the Colorado School of Mines placed on Mount Zion by students, faculty, and a train of burros. Designed by Joe O'Byrne.
May 31, 1908
Lakeside Amusement Park opens.
July 30, 1908
First automobile ascent of Castle Rock on South Table Mountain near Golden made by George Hering of Denver in his new 20-horsepower Stanley Steamer. Hering makes the trip to the top in 12 minutes 45 seconds.
September 10, 1908
First silent movie showing in Golden at the Electric Theatre (later called the Gem) on Jackson Street.
Mother Frances Xavier Cabrini purchases Lookout Mountain property above Jackson Gulch on which she builds a summer home for Denver orphans. The stone house is completed in 1914.
Mount Morrison Incline Railway funicular opens. Built by John Brisben Walker to carry tourists to his resort, the Mount Morrison Hotel and Casino, and as an additional attraction for his "Garden of the Titans," now Red Rocks Park.