Dan and Marie Wilkes are not your typical Mormon missionaries. Many Mormons, especially young men, travel to a new community for a year or two of service and proselytizing when they're in their late teens or early 20s.
The couple, married 46 years, with four daughters and 10 grandkids, never got the chance when they were young — despite a lifelong membership in the Church of Jesus Christ of Latter-day Saints (LDS for short, though members commonly refer to themselves as "Mormons," after the testament they follow alongside the Bible.)