1910s
This is the earliest known logo, from the company's website.
1920s
This logo followed with the removal of the "SINCO" name and its replacement with more symbolic imagery of the company's business.
1930s
Here the logo was further simplified to reflect the primary business of gasoline sales.
1950s-present
This is the first logo to feature the company's advertising mascot, an apatosaur nicknamed "Dino." The company still uses this logo today.