His nomination came as no surprise as he exhibited numerous qualities as a rancher and businessman that helped improve the agricultural community in the state of New Mexico.
As a young man, Mirabal rode the range for the Acoma Land and Cattle Company.
Later, after becoming a notable rancher, Mirabal shipped wool to Albuquerque, New Mexico and Trinidad, Colorado.
During this period, starting in the late 19th century to 1912 Mirabal was nominated as a delegate to the legislative assembly and also to the Constitutional Convention.
These nominations allowed Mirabal to become very influential in the by-laws that established New Mexico as a state from a territory in 1912.