The Tour of California (officially sponsored as the Amgen Tour of California) is an annual professional cycling stage race on the UCI World Tour and USA Cycling Professional Tour. It is the only event on the top-level World Tour in the United States. It was first held in 2006. The eight-day race covers 650–700 miles (1,045–1,126 km) through the U.S. state of California.
A typical edition might begin in the Sierra Nevada in Northern California, travel through the Redwood forests, California’s Wine Country and the Pacific Coast, and finish in Southern California. The 2009 race crossed the Central Valley from Merced to Fresno, with an excursion through the Sierra Nevada foothills, before crossing over to the coast.
With eight or nine of the 20 UCI ProTour teams (known as ProTeams) usually racing, the Tour of California is one of the most important cycling races in the United States. On November 28, 2006, the UCI upgraded it from 2.1(category 1) to 2.HC (French: Hors categorie; English: beyond category), the highest rating for races on the UCI Continental Circuits; the Tour of Utah is the only other 2.HC race as of 2019. On August 2, 2016, the UCI upgraded the race to World Tour status and added it to the 2017 UCI World Tour schedule.
The race was originally staged in February but, the 2010 Tour of California was moved to May, the same time that the Giro d’Italia is held. At the time of the move, it was considered likely that the number of Americans in the Giro and Italians in the Tour of California would decrease. Tour of California organizers sought to make the race a preparatory event for the Tour de France, believing few riders who seek a serious position in the Tour would ride the Giro. Since the change in schedule, the race has continued to be held in May.
Excerpt from Wikipedia. Read the full article here – https://en.wikipedia.org/wiki/Tour_of_California