The Central Valley’s dry, rocky, south-facing slope gives rise to the island’s highest peak (Picacho del Diablo, 2434 feet), and contrasts sharply with the cooler, moist, chaparral-and-oak covered north-facing slope.
The endemic Santa Cruz Island ironwood populations, found only on Santa Cruz, Santa Rosa, and San Clemente Islands, are remnants of once widespread mainland populations which occurred 6 to 19 million years ago.
The Island scrub jay, found only on Santa Cruz Island, is an example of “gigantism,” whereby some island animals evolve to a larger form after years of isolation. This bird is darker blue and one-third larger than its mainland counterpart.
In an effort to restore the process of fire to the islands and enhance the habitat for native plant species, The Nature Conservancy, in cooperation with the National Park Service, has conducted several controlled burns since 1993.
These controlled burns, along with the use of herbicides and monitoring by The Nature Conservancy, have helped biologists determine the best methods to control the dramatic spread of the non-native fennel plant and restore native vegetation.
Varied topography , geologic complexity, and ample freshwater support an array of flora—over 650 plant species. Forty-three, including the northern island bush poppy, are found only on the Channel Islands; eight exist only on Santa Cruz Island.
To encourage the recovery of native plants, The Nature Conservancy removed cattle and sheep from its western 90% of the island by 1988. In 1996, a fence separated the eastern 10% where feral sheep still overgrazed and caused serious erosion. The sheep were finally removed in 1999.
At the turn of the century, Scorpion Ranch was the major satellite ranch on the east end that was used to create an efficient, almost entirely self-contained island ranching and agricultural operation.
Devoted to the protection and management of ecologically significant land, The Nature Conservancy manages the western 76% of Santa Cruz Island. Their island headquarters is located in the island’s central valley.
Painted Cave, named after its colorful rock types, lichens, and algaes, is one of the largest known sea caves in the world, measuring nearly a quarter mile long and 100 feet wide, with an entrance ceiling that rises upward to 160 feet.
Approximately 2,000 Chumash lived on Santa Cruz Island at the time of the first European exploration in 1542. Their extensive trade system with the mainland and manufacturing of shell-bead money helped them survive with limited resources.