The island's earliest known human inhabitants were the descendants of the Chumash Indians who called this island Huima. Although they left no written records of their occupation, their civilization is studied by archeologists through the analysis of that which they left behind. Scientists agree man occupied this island for at least ten thousand years. An additional school of archeologists points to evidence suggesting a far greater antiquity to mans presence, in a setting perhaps contemporary with dwarf mammoths some 29,000 years ago.

The first written record concerning Santa Rosa Island is found in a journal of the expedition of Juan Rodriguez Cabrillo who sailed to the coast of Southern California in 1542-1543 for the King of Spain. In the journal however, the island was called Nicalque, where three Indian villages were observed (Nichochi, Coycoy, and Estocoloco). Although Santa Rosa Island had been claimed for the Spain by Cabrillo, it was the 1793 English expedition of George Vancouver which standardized and finalized the names of the eight Southern California islands, including that of Santa Rosa.

Island Chumash society was vulnerable to both diseases and economic changes introduced by European contact, and as a result, their numbers greatly diminished. In 1805, Fr. Estevan Tapis of Mission Santa Barbara proposed moving the remaining Santa Rosa Islanders from their seven occupied rancherias to a mission on neighboring Santa Cruz Island in order to "bring the Gospel to the inhabitants of the Channel Islands." The island mission was never built, and by the end of the second decade of the 19th century, the last of the island Chumash had moved to mainland missions to learn new ways of animal husbandry and agriculture.

With Mexico's successful revolt against Spain in 1821, unoccupied Santa Rosa Island became subject to the Mexican flag, and 22 years later with the Treaty of Guadalupe Hidalgo to its first private owner, the Carrillo brothers.

On October 3, 1843, Governor Manuel Micheltorena, 13th and penultimate Mexican governor of Alta California, authorized the granting of Santa Rosa Island to these influential and socially prominent brothers who in turn assigned their rights to two of Carlos Carrillo's daughters. Their husbands and business partners, John C. Jones and Alpheus B. Thompson, developed the island's first ranching. In 1859 the island saw the dissolution of the acrimonious Thompson-Jones partnership with a fractional sale to the T. Wallace More family.

By 1862 the More family owned all of Santa Rosa Island. The Mores devoted four decades of ranching efforts. During the More tenure on Santa Rosa Island, the island was used primarily as a sheep ranch. The civil war brought with it a great demand for wool used in the manufacture of soldiers' uniforms. In 1874, 300,000 pounds of wool was produced. By the end of the 19th century the More era came to a close, as Vail & Vickers began their acquisition of fractional interests of Santa Rosa Island from More family heirs.

 Walter L. Vail and J. V. Vickers, together with Los Angeles businessman Carroll W. Gates, had extensive holdings in Arizona and California. The Empire Land and Cattle Company was a successful ranching operation in Arizona with its corporate offices in Los Angeles. Tempered by the collapse of the Kansas City beef market in 1898, the partnership chose to scale back their expansion of the Arizona ranching and focus instead on the many opportunities California had to offer.

In 1901,  Vail & Vickers bought their first shares in Santa Rosa Island. Gates chose not to participate in this venture. That same year the island was stocked with 1,891 yearlings from the Empire Cattle Company. It took an additional 30 years for the Vail and Vickers partnership to acquire the remaining shares of Santa Rosa Island.

Tragically, in 1906, Walter Vail was involved in a street car accident in Los Angeles. He was severely injured and died three days later at the age of 54.

Today as we enter the close of the 20th century, Vail & Vickers continues a tradition of cattle ranching passed down through four generations. Santa Rosa Island is an island where cowboys still ride long hard days, break their own strings of horses, and take pride in their hand-made riatas. Their 65 foot custom cattle boat, Vaquero II, is the only remaining cattle ferry on the west coast of North America. Unknowingly, Vail & Vickers has come to operate what is now the last and only remaining original Mexican Land Grant in Alta California still in existence.

In March 1980, the United States Congress established Channel Islands National Park. As a result of this legislation, in 1986, the Federal Government purchased Santa Rosa Island from Vail & Vickers. In executing the sale, Vail & Vickers retained the right to continue their ranching interest for 25 more years.