Daly City in San Mateo County, California — The American West (Pacific Coastal)

The Ground Beneath Your Feet

Photographed By Sandra Hughes, January 20, 2008

1. The Ground Beneath Your Feet Marker

Inscription. Click to hear the inscription.

Here at Thornton Beach, the ground is not as solid as it seems. The ground itself is made up of a semi-consolidate sedimentary rock from here to Mussel Rock. It doesn't hold together well, which makes the coastline very unstable.

Constant pounding of the surf along Daly City coast undercuts the cliffs. Rain scours and penetrates the soil loosening the rock structure. Gravity pulls the weakened slopes down in slumps and slides. If that weren't enough, the San Andreas Fault runs 1/4 mile from this spot. Ground shaking from earthquakes causes landslides too. Geologists believe the shelf below you, between this elevation and the shore, is a mighty rotational slump triggered by the 1906 earthquake.

This Daly City beach was once accessible by road. In 1982 heavy rains and unusually large tidal action undercut the cliffs from Thornton Beach south to Mussel Rock, causing a massive landslide. Concern over safety keeps the 56-acre property and beach inaccessible.

Topics. This historical marker is listed in this topic list: Natural Features. A significant historical year for this entry is 1906.

Location. 37° 41.862′

Paid Advertisement

Click on the ad for more information.
Please report objectionable advertising to the Editor.

Click or scan to see
this page online

N, 122° 29.79′ W. Marker is in Daly City, California, in San Mateo County. Marker can be reached from Thornton Beach Road west of Skyline Boulevard. Marker is at Thornton Beach State Park along the Ocean Front. Touch for map. Marker is at or near this postal address: 2198 Sky Line Boulevard, Daly City CA 94015, United States of America. Touch for directions.

Other nearby markers. At least 8 other markers are within 3 miles of this marker, measured as the crow flies. If it's Summer, Bring a Sweater (approx. 0.2 miles away); Broderick – Terry Duel (approx. one mile away); Where Daly City Started (approx. 2 miles away); In Honor of Dr. Vic Rowen and Joe Verducci (approx. 2 miles away); Granville House (approx. 2.1 miles away); Monarch's Tale (approx. 2.4 miles away); Mount Olivet Cemetery Office and Streetcar Line (approx. 2.4 miles away); Colma Historical Museum (approx. 2.4 miles away). Touch for a list and map of all markers in Daly City.

Photographed By Sandra Hughes, January 20, 2008

2. The Ground Beneath Your Feet Marker

Photographed By Sandra Hughes, January 20, 2008

3. The Ground Beneath Your Feet Marker

Credits. This page was last revised on June 16, 2016. It was originally submitted on February 1, 2012, by Sandra Hughes Tidwell of Killen, Alabama, USA. This page has been viewed 783 times since then and 61 times this year. Photos: 1, 2, 3. submitted on February 1, 2012, by Sandra Hughes Tidwell of Killen, Alabama, USA. • Syd Whittle was the editor who published this page.