Afterwards, when its peninsular character was ascertained, it was called simply California; but the territory so designated was unlimited in extent.

At the same time, a new visitador, José de Gálvez, was dispatched from Spain with authority to organize and expand the fledgling province.

Expansion came through exploration and colonization expeditions led by Portolá (1769), his successor Pedro Fages (1770), Juan Bautista de Anza (1774–76), the Franciscan missionaries and others.

Independent Mexico retained the division but demoted the former provinces to territories, due to populations too small for statehood.

Inland regions were mostly unexplored by the Spanish, leaving them generally outside the control of the colonial authorities.

The eastern border of upper Las Californias was never officially defined under either Spanish or subsequent Mexican rule.