California produces more milk and butter than any other state in the nation. But its cows also produce toxic gases that form smog. And most of the state's dairies are located in the San Joaquin Valley, already home to some of the nation's dirtiest air. When the State Air Board meets in Fresno tomorrow, officials will decide how many cows a dairy can have before it's subjected to pollution control regulations. Reporter: Sasha Khokha
Please ensure that all comments adhere to our community guidelines. We reserve the right to edit or remove comments that do not follow these guidelines.