Troutdale in the Pines resort hotel opens in Evergreen. Closes in the 1960s, demolished in 1994
Cornerstone laid for new consolidated school known as the Bear Creek Valley School
December 13, 1921
Satanic Coal Mine disaster near Morrison claims lives of six men and injures one as mine fills with deadly firedamp gas
Chief’s Inn, or Ho Cha Nee Stea built as a local tea room and soda fountain for sightseers and prospective land buyers in Indian Hills
April 14, 1922
The first public gathering of the Ku Klux Klan in Jefferson County on the present site of Heritage Square, complete with blazing torches. The targets of KKK intimidation in Jefferson County are Catholics, Jews and blacks.
July 9, 1922
The New York Building on the Jewish Consumptive Relief Society (JCRS) campus dedicated
September 27, 1923
Ku Klux Klan erects and burns a large wooden cross on top of South Table Mountain on Castle Rock above Golden. It becomes major regional meeting place of the Klan.
- First Homecoming celebration for the Colorado School of Mines is held
- Octagon House in Indian Hills is built. Landmarked in 2004
- Center Stage building in Evergreen is built, originally the Meeting House of the Music Conference Complex
- Washington Avenue in Golden is paved for the first time and lined with ornamental streetlights
- The beginning of Tiny Town’s heyday. It has 125 buildings including a genuine pueblo structure with Indians from a New Mexico reservation, and hosts 20,000 visitors per year.
- NaTeSo Pueblo built in Indian Hills as a promotional real estate project by George Olinger. Made of adobe bricks handmade and laid by members of the Navajo, Tesuque and San Ildefonso nations brought up from New Mexico by Olinger.
- Mars Candy Company names Coors its #1 malted milk supplier (during prohibition)
May 2, 1925
Moonshine still explosion causes forest fire in Coal Creek Canyon
- Arvada Flour Mills built by E.E. Benjamin
- Golden Chateau opens as a roadhouse and dancehall on Easley Road in Golden. The building now houses the Golden Elks Club.
- Temple Hoyne Buell designs the third Fruitdale School at 10801 W 44th Avenue in Wheat Ridge. Building design reuses portions of the foundation of the second Fruitdale School which burned in 1926. Added to the National Register of Historic Places in 2013.
- Vera West becomes the first woman editor of a Golden newspaper (wife of George West’s son Harley)
- Conley Coffee Shop, with "the best pies you ever tasted," opens in Conifer
August 7, 1927
Dance hall on top of Golden’s Castle Rock burns down, believed caused by arsonists
April 5, 1928
Sheriff Walter Johnson institutes fingerprinting and photographing each prisoner for identification purposes in the Jefferson County Jail
- Turkey Creek flood damages Tiny Town
- The Grotto at Mother Cabrini Shrine (a replica of the grotto at Lourdes in France) is built. Replaced in 1959.
June 5, 1929
Adolph Coors dies in Virginia Beach, Virginia after falling from a sixth-floor balcony at the Cavalier Hotel