Joseph Allen writes that Mark Cutler, who traveled with him on tour, proposed in a presentation to the travel group that a shift in Church headquarters from Zarahemla to Bountiful apparently took place between 38 B.C. and 30 B.C. By 38 B.C., the Nephites had entered into a great state of apostasy (see Helaman 4:1).
In the fifty and sixth year of the reign of the judges [36 B.C.], there were dissenters who went up from the Nephites unto the Lamanties; and they succeeded with those others in stirring them up to anger against the Nephites; . . . and in the fifty and seventh year they did come down against the Nephites to battle . . . and in the fifty and eighth year . . . they succeeded in obtaining possession of the land of Zarahemla . . . and the Nephites and the armies of Moronihah were driven even into the land of Bountiful. (Helaman 4:4-6)
At 30 B.C., Nephi gave up the judgment seat and committed to preach the gospel for the rest of his days (see Helaman 5:4). In Helaman 5:14 we find that Lehi and Nephi "went forth to teach the word of God among all the people of Nephi, beginning at the city of Bountiful."
According to Allen, it is interesting that as we analyze what was going on in Mesoamerica at this same time period, we can see a shift taking place from Chiapas to Belize, the northern Peten, and southern Yucatan. El Mirador, only thirty miles from Tikal, was very active during this time period, as was Tikal, Lamanai, Becan, Cerros, and many other sites in the region of Dzibanche, a proposed site for the city of Bountiful. Thus we have both textual reasons and cultural reasons for placing Bountiful at Dzibanche. [Joseph L. Allen, "Discovering Bountiful," in The Book of Mormon Archaeological Digest, Vol. III, Issue III (September 2001), p. 6]