The best available evidence for the Book of Mormon continues to support a limited Mesoamerican model. However, Alma 63 indicates that there was a massive northward migration in the mid-first century bc. I argue that these north-bound immigrants spread out over the centuries and established settlements that were geographically distant from the core Nephite area, far beyond the scope of the text of the Book of Mormon. I introduce the Hinterland Hypothesis and argue that it can harmonize the Mesoamerican evidence for the Book of Mormon with Joseph Smith’s statements concerning Nephite and Lamanite material culture in North America. Archaeological and anthropological evidence is used to demonstrate that migrations and cultural influence did in fact spread northward from Mesoamerica into North America in pre-Columbian times.