Portola Expedition, 1769-1770
Diary of Miguel Costansó
Diary of Engineer Miguel Costansó of the exploratory expedition to northern California under the command of Governor Gaspar de Portolá (July 14, 1769 January 24, 1770), from San Diego to the vicinity of Monterey Bay and back. The purpose was to establish a settlement on Monterey Bay and although the Expedition bypassed their goal, they discovered the San Francisco Bay. The purpose of the diary, which Costansó compiled at San Diego from his notes on February 7, 1770, was to make an official report to the Viceroy of New Spain, Carlos Francisco de Croix, and ultimately the King of Spain, Charles III. This edition is based upon Frederick J. Teggart's The Portola Expedition of 1769-1770: Diary of Miguel Costanso, 1911.
| 7/14/1769 | The Portolá Expedition leaves the newly established Presidio of San Diego in search of Monterey Bay |
| 9/8/1769 | Some Expedition members have a close scrape while bear hunting |
| 10/31/1769 | From a high point the Expedition members view the magnificent San Francisco Bay, its islands, and its enormous river for the first time |
| 11/11/1769 | Finally convinced they have gone too far north, the Expedition turns back to the south |
| 12/5/1769 | Frustrated and running low on provisions they have still not located Monterey |
| 12/10/1769 | After erecting a cross on the beach and placing a message at its foot the Expedition heads back to San Diego |
| 1/24/1770 | The explorers arrive at San Diego and happily find the infant establishment still intact |