The term 'Ranch Unit' is composed of two words, 'ACRE' and 'HEAD'. An ACRE is a unit of area measurement equal to 43, 560 square feet, commonly used in the United States for measuring land. A HEAD is a unit of measurement for livestock, typically referring to one adult animal. Therefore, a Ranch Unit is a unit of measurement for land and livestock, usually referring to a certain amount of land and the number of animals it can support.