Monterey Jack (sometimes shortened simply to Jack cheese) is an American semihard cheese, customarily white, made using cow's milk. It is commonly sold by itself, or mixed with Colby to make a marbled cheese known as Colby-Jack (or Co-Jack). Cheddar-Jack and Pepper Jack varieties are also available. A common misspelling is "Monterrey" Jack, presumably in confusion with the Mexican city of Monterrey.