Crossing San Mateo Creek just above its canyon, Portola's party proceeded south along Laguna Creek and camped on a lake which Portolà called Laguna Grande (Spanish for 'Great Lake'), now covered by Upper Crystal Springs Reservoir.

Filoli, the estate of Spring Valley Water Company tycoon William Bourn, is now an historic site.

[7] Adobe Gulch is the northernmost of several tributaries (and the only one named by the USGS) that descend the eastern flank of the Santa Cruz Mountains to Upper Crystal Springs Reservoir (and historically, Laguna Creek).

San Mateo County historian Frank Stanger cited sizeable groves of redwoods (Sequoia sempervirens) in the Laguna Creek watershed.

[16] A large redwood tree remains on Laguna Creek between the lower Filoli parking lot and main entrance gate.

On Cahill Ridge (just west of San Mateo Creek and east of Pilarcitos Creek, at an altitude of 1,000 feet, Oberlander measured fog drip beneath tanoak (Lithocarpus densiflorus), coast redwood and three Douglas fir trees, the latter 125 feet tall.

The Douglas fir produced 7–17 inches (180–430 mm) of fog drip and appeared to provide unique conditions supporting the orchids giant helleborine (Epipactis gigantea) and phantom orchid (Cephalanthera austiniae), since these plants were found exclusively in these moist ridge tops.

[19] The pond is the site of a restoration effort by the San Francisco Public Utilities Commission which will include removal of non-native eucalyptus trees and planting of native oaks and grasses.

[20] Although Laguna Creek generally runs dry in summer, on October 17, 2012, two-year-old rainbow trout (Oncorhynchus mykiss) were observed in cold, spring-fed perennial pools along the Filoli property.