No particular landmarks or monuments mark the islands. But each one has its own subtle, and unique, characteristics. Plants exclusive to this island include the Santa Barbara Island live-forever, shrubby buckwheat, chicory and creamcups. Endemic birds nest on Santa Barbara, including the horned lark, orange-crowned warbler and house finch. The Santa Rosa subspecies of Torrey Pine is one of the rarest pines in the world, the last vestige of a once-huge Pleistocene forest.
Sites contain some of the oldest evidence of human presence in North America.
The park is named for this strange form of yucca, and the trees may be found in clusters throughout the western half of the park. The park's massive boulders are hard to miss, and they crop up in many places. These shade a trail said to be a cattle rustlers' hideout in the old days. A concentration of cactus plants and other Colorado Desert flora await discovery on a nature trail that a variety of creatures also find appealing. Birds flock to the palm oasis here.