I would like to know how I can find a French fry producer who was in business back in 1970's and 1980's, who supplied French fries to eateries in Idaho. Can you please help me out?

All the major French fry processors in the United States were in business back then, Simplot and Ore-Ida were the largest in Idaho. Simplot invented the frozen fry and started up a plant in 1960 in Burley.

Hope this helps with your project.

Contact info for the processors is here: Idaho® Potato Processors