In 1842 Mexico granted Rancho San Geronimo, which includes much of the present-day Estero Bluffs State Park, to Rafael José Serapio Villavicencio.

The Trust imposed a conservation easement that limits and prohibits certain activities on the land, such as the construction of public restrooms or the use of running water.

[5] The park's foundation is built from rocks of the Franciscan Assemblage which dates back to around 140 million years, placing its formation sometime during the late Jurassic Period.

Due to a shifting of tectonic plates, the land was raised above sea level to create the seaside cliffs that can be observed today.

In the ocean, the harbor seal and sea otter, a threatened species, utilize the intertidal areas for resting and foraging.

[3] Rabbits, ground squirrels, striped skunks and other rodents call the grasslands and coastal scrub of the park home.