In 1971, the It Is Written production studios moved to the Adventist Media Center in Thousand Oaks, California. In 1975, Vandeman began conducting Revelation Seminars."Revelation Seminar" in Historical Dictionary of Seventh-day Adventists by Gary Land, p246 The seminars consisted of a one-day, eight-hour Bible study followed by a luncheon. Over a course of 10 years, tens of thousands of It Is Written viewers traveled hundreds of miles to attend one of 300 seminars.
