Much of the base is rugged, mountainous, and undeveloped; predominant groundcover includes chaparral with coastal sage scrub and oak woodland. Because of its protected nature—none of the backcountry areas are open to the public or to any kind of development—the base contains some of the highest quality coastal habitat remaining in southern or central California. It is home to numerous threatened or endangered species, including Gambel's watercress (Nasturtium gambellii). The western terminus of the Santa Ynez Mountains is on the base, and is dominated by Tranquillion Peak, which rises above sea level. An optical tracking station is located at the top of the peak, which overlooks the various space launch complexes. The Amtrak Coast Starlight and Pacific Surfliner trains travel along the coast, providing a splendid view and one of the few ways for the public to see these remote areas. Conversely, State Route 1, California's Pacific Coast Highway, avoids these coastal protected areas and instead turns inland to serve the base's eastern side.