Santa Rosa Island,located 40 nautical miles from the Channel Islands National Park visitor center in Ventura, is the second largest island in California at approximately 53,000 acres in size.he island’s relatively low profile is broken by a high, central mountain range, rising 1,589 feet at its highest point. Its coastal areas are variable, ranging from broad, sandy beaches gently sloping toward a dynamic ocean to sheer cliffs plunging toward the turmoil of a sea intent on changing the contour of the land.About 500 plant species can be found within nine plant communities, including six plant species found only on Santa Rosa and nowhere else in the world. One of these species, the Santa Rosa Island subspecies of Torrey pine, is considered one of the rarest pines in the world.Island also hosts over 100 bird and three mammal species (including the island’s largest native mammal, the endemic island fox); 2 amphibian and three reptile species; and colonies of seabirds, seals, and sea lions.