Comparison of topographic maps from 1896 and 1939 illustrates the extreme modification in the lower reaches due to urban development from the rapidly expanding population.
[3] Prehistorically the banks of San Bruno Creek were settled by the Buriburi tribe of the Ohlone, who have presumably lived in the area since as early as 2000 BC.
One of the earliest maps showing San Bruno Creek appeared in 1893, prepared by Andrew Cowper Lawson, professor of geology at the University of California, Berkeley.
The upper one and a half miles (2,400 m) of San Bruno Creek is the most rugged and natural reach as the stream winds through steep canyons of about 45 degrees in slope.
The understory also includes the following wildflowers: evening primrose (Renothera ovata), wild radish (Raphanus satira), wild cucumber (Marah fabaceus), scotch broom (Cytisus scoparius), miners lettuce (Montia perfoliata), fillaree (Erodium cicutarium), vetch (Vicia americana), sweet clover (Melilotus indicus), lupine (Lupinus sp.