Before the establishment of a lighthouse at Point Piedras Blancas, sea captains depended upon navigational charts, their sightings of natural landmarks, and their own navigational ability to guide them. Before there was a lighthouse the large white rocks would have been a visual aid to navigators. The name, Piedras Blancas, means “white rocks” in Spanish.

The earliest indication that a light station would exist at Point Piedras Blancas occurred on May 22, 1866 when W.B. Shubrick, Chairman of the Lighthouse Board, wrote to J. M. Edmunds, Commissioner of the General Land Office, requesting that twenty acres be reserved on the point for lighthouse purposes. This request was promptly forwarded to James W. Harlan, Acting Secretary of the Interior and from there to the President of the United States. On June 8, 1866, Andrew Johnson replied saying, “Let the lands within described be reserved for lighthouse purposes as recommended by the Acting Secretary of the Interior”.

On June 10, 1872, an appropriation of $75,000 was approved by congress for a first order light and fog signal and before the end of the year the actual site for the light was selected. In early 1873 a detailed survey of the site was completed and a map had been made.

Captain Ashley was appointed to superintend construction. He had previously proven his ability when he completed construction of a similarly designed lighthouse at Point Arena.

However, work did not begin until April of 1874 when material for the brick and steel tower was shipped under contract with Goodall, Nelson and Perkins, prominent coastwise shippers of the day. The materials came from San Francisco on the San Luis, under Captain Alexander and were brought ashore at the beach south of the point on April 26^th, 1874.Twenty-five to thirty men were employed in construction which was not completed until the following year.
 
The tower of the Piedras Blancas lighthouse was the third of its kind to be constructed on the Pacific coast. A double wall of brick with an air space between keeps the structure from sweating and deteriorating in the most sea air. Originally the tower reached a height of 110 feet, with the the focal plane 141 feet above mean high water. The diameter at the base is 34 feet. The tower contains a circular iron stairway which reached to the light.

In 1872, Henri Lapaute of Paris, France completed manufacture of the first order Fresnel lens for the Piedras Blancas Light Station. In the center of the lens assembly was an ardent vapor light source consisting of a pool of lard oil, and later mineral oil, with five wicks in it. This was later replaced with a kerosene lamp which consumed four to five tons of kerosene per year, all of which was carried up the circular staircase by the keepers. The light could be seen on a clear night from the mast of a sailing vessel as much as 25 miles to sea.

The light was rotated by a clock mechanism to flash once every 15 seconds, controlled by the measured fall of a weight attached to a cable running down the center of the tower. The mechanism was also made by Henri Lapaute in 1872. The lighthouse keepers cranked a drum, rewinding the weight every few hours. Each evening when the mechanism was put in motion, the timing of the rotation had to be regulated by adjusting the feathering air vanes on the governor. Three men were required to maintain the station, working shifts during the night. A large two-story triplex house was provided for the men and their families.

In 1916 the lens was modified to produce two flashes every 15 seconds. This required changing the speed of rotation from one revolution every two minutes to one revolution every minute. 

The lighthouse was first put into operation in February, 1875. Stephen H. Morse was the head keeper until 1879 when Captain Lorin Vincent Thorndyke was placed in charge. He served as its head keeper until he retired in 1906 at the age of 67. During the nearly 30 years Captain Thorndyke was in residence there, no shipwreck occurred, a credit to the efficiency of the warning system and the men in charge of the light.

Captain Thorndyke was born in Camden, Maine and claimed to have circumnavigated the globe five times before becoming a coastwise sailor. He finally quit the sea to become keeper of the lighthouse at Piedras Blancas. The Captain’s wife, Elizabeth Jarmon, was a younger sister of Mary Jarmon who was married to Thomas Evans, owner of a ranch near the light station. Their sons, Lorin V. and John Emory, were born at the lighthouse.

Elizabeth died when her youngest son, John Emory, was four years old leaving the responsibility of raising two boys upon the shoulders of the Captain. After a brief and unsuccessful second marriage, Captain Thorndyke married Margaret Jarmon in 1897, sister to his first wife, Elizabeth and to Mary Jarmon Evans.

Supplies were brought to the light station by a government lighthouse tender ship approximately three or four times a year. Kerosene for the light, coal for the three families, flour and other staples and lighthouse supplies were delivered at a wharf built against the steep ocean cliff on the south side of the point. In between tender visits, a supply ship appeared at irregular intervals.
 
Although the original $75,000 allocation was supposed to include a fog signal, it was not built at that time because the funds were exhausted in constructing the tower. Additional funds were allocated in 1906 and the fog signal building was constructed then in addition to a separate dwelling for the head keeper.

At the age of 67 Captain Thorndyke decided it was time to retire. He used the installation of the fog signal as his excuse, saying that the noise it created was so great he could no longer work under the strain. According to Lorin, Jr., it did not bother him particularly.

After retiring, the Captain and Margaret settled at San Simeon where, for several years, they assisted Lorin Thorndyke, Jr. and his wife at the store and hotel which he now owned. Following Captain Thorndyke's resignation, civilians continued to be in charge under the supervision of the U. S. Lighthouse Service. In 1939 the Coast Guard took over management of the station, at which time enlisted personnel replaced civilian employees.

The lens, lantern room, ornate railing and the upper portion of the tower were removed by the U. S. Coast Guard in 1949 when they judged that the tower could no longer safely support the lantern room due to a large crack about 25 feet down from the top. The crack was the result of an earthquake occurring on the last day of 1948 with an epicenter quite close to the lighthouse. The lens was then loaned to the Cambria Lions Club for care and display in Cambria. It now stands near the Veterans' Memorial building on the Pinedorado grounds in downtown Cambria.

In place of the old light an automatic electric drum aero-rotating beacon with a 36-inch lens was installed. Operating in conjunction with a 1,000 watt electric bulb, it was capable of casting a light beam a distance 18 miles from its altitude of 141 feet above sea level.

In 1960 the head keepers house and the large, two-story triplex which served the station personnel for so many years were removed and replaced with four cinder block buildings which still exist.

The Coast Guard crew was rotated frequently. Children of the young families in residence at the station attended school in Cambria.

In May, 1999, the aero beacon failed and, in September, the Coast Guard replaced it with a smaller, less intense flashing lantern with a visibility of only about 10 miles. Although area residents were unhappy with the smaller light, The Coast Guard maintained that a brighter light was much more expensive and was not necessary due to advances in navigation technology.