While we know that Mosiah1 and his group had to flee out of the land of Nephi, we are not told in what direction (other than "down"); however, from the geographic description given in Alma 22:27-29, we learn that at that time, the more expanded general land of Zarahemla was somewhat north of the more expanded general land of Nephi, and that they were separated by a "narrow strip of wilderness." We are also not told specifically how long the journey was; however, from the journey of Alma1 when he fled from king Noah and eventually found his way to Zarahemla, we can calculate the general distance between the City/Land of Nephi and the City/Land of Zarahemla as totalling a little more than 21 days. [Alan C. Miner, Personal Notes] [See the commentary on Mosiah 24:25]
They Departed out of the Land of Nephi into the Wilderness Until They Came Down into the Land of Zarahemla
Brant Gardner notes that upon reading that Mosiah "departed out of the land into the wilderness" (Omni 1:13), the reader might rightfully ask why he chose to go in the direction he did. Of course the Lord was leading him, but it seems as though the direction he went in was natural for him. Could it be that he was following a trade route? Trade routes are difficult to trace archaeologically, but they may be presumed when an identifiable trade good moves from one location to another.
In the case of Kaminaljuyu (a proposed site for the city of Nephi) a major export was obsidian. The creation of obsidian leaves sufficient traces of its location that pieces of obsidian found long distances away can be accurately traced to their source. The Kaminaljuyu obsidian is known as El Chayal. The trade in El Chayal obsidian in the early years of the Book of Mormon would have been down through the coast, but at the time period we are examining, it appears that a primary distribution channel had been developed whereby El Chayal obsidian was traded into what is now Veracruz, Mexico, which is in a direction generally northwest of Kaminaljuyu.
Thus there were already cultural predispositions to move north, and the sure knowledge that there were friendly towns in that direction.
Additionally, in the time period in which Mosiah and his followers would have arrived at Santa Rosa, Chiapas Mexico (a proposed site for the local land of Zarahemla), certain pottery shows ties to Kaminaljuyu--ties sufficient to be termed "perhaps the closest linkage of our material to other regions." Thus Mosiah's flight northward has a plausible setting. [Brant Gardner, "Book of Mormon Commentary," http:// [www.highfiber.com/~nahualli/LDStopics/Omni/Omni1.htm], pp. 16, 38]