[1] Obregón was born the son of an encomendera in the Spanish colony of New Spain.
At the age of 19 Obregón joined up with a Spanish expedition to California, from which he returned with travel experience.
In 1554 at the age of 20 he joined the expedition of Francisco de Ibarra to explore the frontiers of Spanish territory and to secure mineral resources.
The expedition was a success, founding several settlements and allowing the Spanish to colonize Zacatecas.
[1][3] After cataloging his own life, he continued to publish the accounts of other Spanish expeditions, such as that of Antonio de Espejo.