It drains a large coastal watershed that includes the city of San Luis Obispo, emptying into the Pacific Ocean at Avila Beach.

[4] After emerging from the tunnel it flows past Mission San Luis Obispo de Tolosa, and then receives Stenner Creek from the right just upstream of Marsh Street.

[5] Approaching its mouth, the creek forms a small estuary before emptying into the Pacific Ocean at San Luis Obispo Bay, just west of Avila Beach.

[9] North American beaver (Castor canadensis) have been thought to be non-native to San Luis Obispo Creek but Bolton recorded in "Anza's California Expeditions" that in April 1774, Father Cavaller of Mission San Luis Obispo de Tolosa gave Juan Bautista de Anza "thirty-odd beaver skins" along with other local gifts including fine Indian baskets and "the skins of eight bears, the animals for which the region was renowned".

Other barriers have been removed as well, often by creating notches in the middle to concentrate low flows or adding rock weirs to back up the water over an obstacle or provide a more gradual change in elevation.