Gabriel Moraga (1765 - June 14, 1823) was a Spanish army officer in the Viceroyalty of New Spain, an Alta California explorer, and son of the pioneer José Joaquín Moraga. Although born in Fronteras, Sonora, Mexico, Moraga spent most of his life in Alta California. He died in Santa Barbara.
The elder Moraga was a member of both expeditions of Juan Bautista de Anza to explore and consolidate the north-western limits of Spain's colonial claims in Alta California. The first expedition in 1774 established a new overland route from Sonora, Mexico to Mission San Gabriel. The second, in 1775-6, went as far north as San Francisco Bay.
The second expedition included a group of colonists for settlement at the newly established San Francisco Presidio, Mission San Francisco de Asís and Mission Santa Clara de Asís. The colonists included the Moraga family. José Moraga became commander of the garrison at San Francisco Presidio, and Gabriel became a soldier as well.
As a corporal, Gabriel Moraga was appointed comisionado (military administrator) of the Pueblo of San Jose, some years after its establishment by his father in 1777. When another civilian town, the Villa de Branciforte, was established in 1797 (part of today's city of Santa Cruz), Corporal Moraga was transferred to the same position there and was replaced at San Jose by Corporal Ignacio Vallejo, father of Mariano Vallejo.
Gabriel Moraga was one of the first Europeans to see the Central Valley of California. He led the first official Spanish expeditions to explore the valley in 1806-1808. Many of the names which Moraga gave to places in the region (especially rivers) have survived, often in shortened and/or anglicized form:
Not all of Moraga's place names have survived. Today's Stanislaus River was named Rio de Nuestra Señora de Guadalupe by Moraga. Even at the early date of Moraga's expedition, the name was redundant. Today's Guadalupe River was named in 1776 by the de Anza expedition.
Many years after Gabriel Moraga's death, his widow Ana Joaquina Alvarado (1788-1863) was granted (in 1841) the Rancho Cañada Larga o Verde, not far from Mission San Buenaventura. Gabriel and Ana's son Joaquín was co-grantee of Rancho Laguna de los Palos Colorados in present-day Contra Costa County, part of which is now the city of Moraga, California.