We see here the tick of time between the age of the dinosaurs and the beginning of the age of the mammals at this location where back in 1943 geologist Roland Brown discovered the first North American evidence of the K–T boundary on South Table Mountain. The lava capped tops of South Table Mountain have protected this geological wonder for 63 million years. Although this is not designated as the "exact" spot where this discovery happened, I find it an appropriate example of time's passage. In the distance, Denver, a flourishing mega-city with all the technological wonders available to modern man awaits just minutes from this ancient crack in the Earth which is probably not much different than when man first began his quest for mechanized mastery.
K is the traditional abbreviation for the Cretaceous period, and T is the abbreviation for the Tertiary period. The boundary marks the end of the Mesozoic era and the beginning of the Cenozoic era, and is associated with the Cretaceous–Tertiary extinction event, a mass extinction. With "Tertiary" being discouraged as a formal time or rock unit by the International Commission on Stratigraphy, the K–T extinction event is now called the Cretaceous–Paleogene (or K–Pg) event by many researchers.