Timeline of the Portolá expedition

This timeline of the Portolá expedition tracks the progress during 1769 and 1770 of the first European exploration-by-land of north-western coastal areas in what became Las Californias, a province of Spanish colonial New Spain.

Missionary Juan Crespi kept a diary describing the group's daily progress and detailed descriptions of their locations, allowing modern researchers to reconstruct their journey.

The Portolá expedition was the brainchild of José de Gálvez, visitador (inspector general, a personal representative of the king) in New Spain.

On his recommendation, King Charles III of Spain authorized Gálvez to explore Alta California and establish the first permanent Spanish presence there.

[1] Gálvez was supported in the planning of an expedition by Carlos Francisco de Croix (Viceroy of New Spain), and Father Junípero Serra (head of the Franciscan mission to the Californias).

Rivera led the first group, consisting mainly of soldiers, scouts and engineers to prepare the road and deal with hostile natives.

Serra came north by sea to make the Mission San Carlos Borromeo del rio Carmelo (moved a few miles south from its original Monterrey location) his headquarters.

The rough-to-non-existent trail was over 400 miles from Loreto north to Velicatá, and land travel can't have been much faster than the 5–10 miles/day the diarists noted later on.

The hunters also saw and reported that further progress to the north was blocked by the wide bay entrance channel (later named the Golden Gate by John C. Fremont.

As Crespí wrote: We conjectured also from these reports that the explorers could not have crossed to the opposite shore which was seen to the north, and consequently, would not succeed in exploring the point which we judge to be that of Los Reyes, for it would be impossible in the three days that they were to be gone to make the detour that they would unavoidably have to make to round the estuary, whose extent the hunters represented as being very great.Crespí also quotes a revealing passage from the expedition's guidebook, in which Cabrera Bueno described what he called the "Bahia de San Francisco": Through the opening in the center enters an estuary of salt water without any breaking of the waves at all, and by going in one will find friendly Indians and can easily take on water and wood.Crespí thought that this passage described the entrance to the huge "estuary" the scouts had just found.

If Crespí's interpretation was correct, then the discovery of San Francisco Bay happened many years earlier (Cabrera Bueno's Navegación Espéculativa y Práctica was published in 1734).