In 1853, a United States Post Office was established here at the crossroads of what was then called the town of Dos Piedras, meaning two rocks in English. Somehow it became singular, Two Rock, in translation, and in the naming of the Post Office.

Dos Piedras goes way back to pre-Spanish days when the rocks served as a landmark and reference point along the ancient Indian trail that ran from Bodega Bay to the inland valleys and into the Sierra. The trails, tend to follow along the ridgelines and high ground because most of the flat land was swampy and muddy. Dos Piedras was referred to time and time again in the earliest annals of Native American migrations and seasonal travels.

The Dos Piedras trail was used extensively by the earliest Spanish explorers and settlers, traveling to and from Bodega Bay, the only seaport of any consequence between San Francisco and Fort Ross. This route was followed by such men as General Jose Figueroa, wisest and best-loved of all California governors, and the gallant and learned Don Juan Alvarado, who came in 1838, the year before he became governor. With the latter, came Mariano G. Vallejo who was later made commander of the northern frontier with the rank of general.

The old battle cry of the Spaniards was "Santiago"! (St. James was the patron saint of the Conquistadors.) When they built a military outpost in Two Rock, on the old Indian trail, they called it Santiago de las Dos Piedras, St. James of the Two Rocks. They believed that here they must stem the Russian advance with the settlement of this area.

General Vallejo’s duty was to settle and create a barrier of defense against the Russians who, by then, had become well established just to the northwest at Fort Ross. Taking the ancient landmark of the two rocks as central point, he granted four huge ranchos, all cornering at this spot.

To the south, lay the great Rancho Laguna de la Santiago, containing 25,000 acres and embracing the heart of Two Rock valley, with headquarters at Santiago, and all of Chileno Valley. This magnificent gift, of a kind unparalleled in the history of any government’s generosity to a single citizen, was granted to a soldier of the ranks, Bartolome Bojorques. His stepdaughter, Seniorita Talamantes, married a Chilean, who brought up his retainers from Chile when he came to manage the Laguna Rancho, hence the name Chileno Valley.

A young Captain, Juan Nepomisena Padilla, only 21 years old, was made guardian of these northern trails and to him was granted the great rancho which touched the two rocks to the east. It was called El Roblar de la Miseria, The Oak of the Misery. This rancho contained 16,000 acres, reaching from Two Rock, through Liberty and over to Roblar and Hessel.

General Vallejo must have had a special fondness for young Captain Padilla, for besides the princely rancho, he gave him the Rancho Balsa de Tomales, which cornered with the Blucher and Robler Ranchos at the two rocks. The name means "the Pool of the Tomales Indians," which Mrs. Rose Linebaugh, an early Two Rock historian believed referred to Burbank’s Lake.

Some of the boundaries of these ranchos are now difficult to trace, but there still remains evidence of the old Spanish ditches which were once used to mark boundaries. The Spanish loved open fields so, if they had to make a boundary, they made their men dig a ditch. These ditches were wide and deep enough to turn cattle. One of them is still visible on the Linebaugh place.

The Blucher Rancho was granted to a Swiss saloonkeeper who made the first survey of the town of Yerba Buena, which later became San Francisco. He named the rancho for his mother, Madame Blucher, and soon sold it to Captain Stephen Smith of Bodega. Smith deeded half of it to his heirs in Baltimore, thus causing much trouble later when parcels were sold to the American settlers and title was sought.

Many other travelers of note passed between our two rocks during their early history. Three, surely worthy of mention, were the beautiful Princess Helena de Gazarin, wife of the last governor of Fort Ross. She became a permanent part of our history when the mountain and, later, the town of St. Helena were named for her. It is also well documented that in 1846 the great pathfinder, General John C. Fremont, galloped up the trail between the rocks with his wild band of horsemen, one of whom was Kit Carson.

Many of the early American settlers originally came from Germany, Denmark, Italy, Ireland, and Switzerland. Many of their descendants still live in the valley today.