I Iz For Fiz'

Fiz is a reference to Fizbee, a character from Clark Oil's 1959-1961 advertising campaign. The campaign involved radio ads and accompanying road maps and pins modeled after Clark's logo. 

Clark was founded in 1932 by Emory T. Clark, who opened the first Clark gas station in Milwaukee, WI. The brand expanded from Milwaukee across the American Midwest until it faced financial difficulties in the 1980s. These troubles led to many shifts in ownership, most recently in 2003 when Clark Oil became Clark Brands, LLC. In this current form, Clark operates gas stations in thirty-two states and the District of Columbia.