Denniston Creek is a 4.4-mile-long (7.1 km)[1] coastal stream in western San Mateo County, California.
Denniston Creek rises on the western slopes of Montara Mountain and discharges to the Pacific Ocean at Pillar Point Harbor somewhat north of El Granada Beach.
The watershed of Denniston Creek is made up of relatively permeable sandy soils capable of significant recharge to its aquifers, which supply a moderate amount of potable water to the local area.
[2] This upper pocket groundwater complex feeds down-basin alluvial fan deposits on the coastal plain.
[3] At the mouth of Denniston Creek, the stream cuts through a gently sloping marine terrace plain of alluvium.