Green Oaks was a headquarters ranch for the Steele Brothers, a pioneer dairy firm. Although neither the first to have a dairy nor the first to make cheese in California, the Steeles were the acknowledged pioneers in cheese sales and marketing. For three decades, the company was the largest producer of cheese in California.

The house at Green Oaks Ranch was the first built by any of the Steeles in California on their own landholdings. It was the home of Isaac Chapman Steele, the last surviving member of the firm and the only one with a lifetime career in the dairy industry.