City history
Founded during the 1858 Pikes Peak Gold Rush on Indigenous Arapaho land, Denver became the central anchor city for Mountain Standard Time aligned with the 105th Meridian West.
Chapter one
Indigenous name
"Tallow River"
Indigenous Arapaho, Cheyenne, and Ute peoples maintained seasonal encampments at the confluence of Cherry Creek and the South Platte River long before gold prospectors arrived. In the Arapaho language, the area was named Niineniiniicie, referencing the tallow or fat river.
Tallow River
Arapaho name for the seasonal encampment area at the confluence of the South Platte River and Cherry Creek.
Mountain city
The first European-American gold rush settlement in modern Denver along the South Platte River, established by prospectors from Lawrence, Kansas.
Named after St. Charles, Missouri
Townsite staked on the east bank of Cherry Creek shortly after Montana City, before being claim-jumped by Kansas land speculators.
Gold town (from Latin aurum)
Settlement established on the west bank of Cherry Creek by Georgia prospectors, named after Auraria, Georgia, before merging with Denver in 1860.
Named for James W. Denver, Governor of Kansas Territory
Staked by General William H. Larimer Jr., who named it after Kansas Territorial Governor James W. Denver to curry political favor.
Shortened form of Denver City
The city dropped 'City' from its official name around the time it was selected as the permanent capital of Colorado Territory.
Chapter two
Settlers in early Denver City set local clocks to mean solar time based on the city's meridian. True solar noon in downtown Denver occurs approximately 20 seconds behind the 105th Meridian.
On 'The Day of Two Noons,' Denver adopted Standard Railway Time along the 105th Meridian West (UTC-7), positioning the city as the primary urban reference point for the Mountain Time Zone.
Congress codified federal standard time zones and introduced nationwide daylight saving time during World War I, advancing Denver's clocks to Mountain Daylight Time (UTC-6) during summer months.
Denver observed continuous year-round Mountain War Time (UTC-6) throughout World War II from February 1942 until September 1945 to conserve electrical energy.
The federal Uniform Time Act standardized daylight saving time observance across Colorado, establishing uniform statewide spring-forward and fall-back transition dates for Denver.
Chapter three
The completion of the Denver Pacific Railway connected Denver to Cheyenne, Wyoming, forcing local businesses and stations to strictly synchronize clocks for rail timetables.
The University of Denver opened Chamberlin Observatory, housing a 20-inch refracting telescope and precision meridian clocks used to determine exact astronomical time for local time distribution.
The 330-foot Daniels & Fisher Tower was completed with four 16-foot Seth Thomas clock faces and a 2.5-ton bell, becoming Denver's tallest landmark and main civic timepiece.
The National Bureau of Standards relocated its radio propagation laboratories to nearby Boulder, bringing atomic clock development and precision time signal research directly to the Denver metro area.
NIST implemented TV common-view clock synchronization using television signals broadcast from Lookout Mountain overlooking Denver, keeping regional research clocks accurate to within 0.5 microseconds.