Keystone beer is a product of the Coors Brewing Company in Golden, Colorado. It was first introduced in Chico, California in September 1989. Keystone can be found in can, keg, and occasionally bottled form. Its "Light" variety is commonly labeled as "high school beer" due to it being very inexpensive and thus popular with young adults in the United States. Keystone Light has a 4.2% a concentration less than standard American lagers, and roughly equal to other macro "light" brews.