Police said the money was stolen from a fair deposit bank late Wednesday night.
"There is an ongoing investigation into an incident that may have occurred at Cal Expo," said Cal Expo spokesman Cory Egel.
The police said perimeter searches, air support and K-9 units are assisting in the search for the robbers. They are described as two black men who were wearing red and black fair food service uniforms.
This article originally appeared on KCRA.com.