For more than 70 years, a 34-foot illuminated cross looming over the Cahuenga Pass has been one of the landmarks by which motorists mark their passage between downtown and the San Fernando Valley. In fact, the cross was conceived not as a purely religious monument, but as a memorial to one of Hollywood’s pioneers, Christine Wetherell Stevenson, the heiress to the Pittsburgh Paint fortune who helped arrange construction of the Hollywood Bowl. She was also an aspiring playwright who wrote “The Pilgrimage Play,” a pageant about the life and teachings of Jesus Christ. In 1920, Stevenson chose 29 acres across...