After discovering San Francisco Bay from Sweeney Ridge on November 4, 1769, the Portolà expedition descended what Portolà called the "Cañada de San Francisco", now San Andreas Creek (or possibly San Mateo Creek). "Laguna Grande" is where the party camped (now covered by the Upper Crystal Springs Reservoir). The Laguna Grande place name is also shown on the 1840s diseño del Rancho Cañada de Raymundo and an 1856 plat. The campsite is marked by California Historical Marker No. 94 "Portola Expedition Camp". They camped here a second time on November 12, on their return trip.