Jon Tollenaar is a second generation dairy farmer in Elk Grove. He is a past board member of the Sacramento County Farm Bureau and sat on the Feed Advisory Board and Feed Safety Committee for the California Department of Food and Agriculture. He also served as a board member with the Dairy Herd Improvement Association. Tollenaaar's wife Tami, who helps manage the family cattle operations, is active in industry and youth participation programs, including the North American Intercollegiate Dairy Challenge. The Tollenaars are active in issues including management and analysis, animal identification systems, genomics, dairy beef quality assurance, the worldwide dairy update, and the new industry economy.

The 300-acre Tollenaar Ranch and Dairy is home to nearly 2,000 head of cattle, primarily Jersey cows. The Tollenaar's Jerseys have been top-ranked animals across the country, recognized for their superior genetics.

In the past five years, the Tollenaars, in partnership with SMUD and the federal government, worked to develop solutions to the ongoing challenges of processing waste and reducing greenhouse gas emissions. As a result, the Tollenaar Dairy is home to one of the two operating dairy digesters in Sacramento County.