Mulek's name suggests it was the first city established by the Mulekites, who landed in Desolation but did not remain there because of the destruction caused by the Jaredite civil war (Alma 22:31, Ether 10:21). Because Mormon uses the phrase "the place of their first landing," I conclude that the Mulekites did not migrate overland into the land southward, which the Jaredites called Bountiful, but boarded their ship(s) and sailed to their second landing. Webster's 1828 Dictionary defines "landing" as "A place on the shore of the sea or of a lake, or on the bank of a river, where persons land or come on shore, or where goods are set on shore."
Mormon doesn't provide any information about the second landing, or the Mulekite colonization before they were joined by the Nephites under King Mosiah I. He does say that by the time Mosiah's people found them, the Mulekites "had become exceedingly numerous. Nevertheless, they had had many wars and serious contentions, and had fallen by the sword from time to time" (Omni 1:17). Mormon does not specifically state that Zarahemla, the King of the Mulekites, had relocated their capital city to Zarahemla.
The challenge we face locating Mulek is that most of its descriptions come from its relationship to the city Bountiful, and Mormon doesn't provide very specific information about the location of Bountiful, either. We know the city Bountiful is in the land Bountiful, which stretches from sea to sea and which borders the Isthmus of Tehuantepec. But, Mormon provides no information about the size of the land Bountiful, or about the city's location except in relationship to the city Mulek. All we can do is take the tidbits of information Mormon provides and identify a general location for the two cities.
- Mulek is "on the east borders by the seashore" (Alma 51:26), and its capture is part of the Lamanite plan to “harass the Nephites in the borders by the east sea, and . . . take possession of their lands as much as it was in their power” (Alma 52:13).
- Mulek is the last Nephite stronghold the Lamanites take before advancing on the land Bountiful (Alma 51:28).
- The Lamanites "marched to the borders of the land Bountiful, driving the Nephites before them and slaying many" (Alma 51:28).
- Moroni invited the Lamanite army to "meet them upon the plains between the two cities" (Alma 52:20).
- To position his army as part of the strategy to lure the Lamanites out of Mulek, Moroni took his army and "marched in the wilderness, on the west of the city Mulek" (Alma 52:22).
- Teancum, positioned with his men "near the seashore," "began to retreat down by the seashore northward" when the Lamanites from Mulek marched against him (Alma 52:22-23).
Mormon's account does not mention the crossing of any rivers when the Lamanites advance from Mulek to Bountiful, yet this placement, with Mulek on the east of the Usamacinto and Bountiful west of the Grijalva, would require the crossing of both rivers. This is not unusual, considering that he didn't mention the Lamanites crossing the river Sidon as they marched from city to city along the east coast line, which they certainly would have had to do, since the Sidon empties into the east sea. Mormon is simply silent regarding the locations of other rivers in ZARAHEMLA and only mentions military crossings of the river Sidon when the battles take place as part of the crossing.
As for how the Nephites and Lamanites crossed rivers, expecting a bridge system in ZARAHEMLA is perfectly reasonable. ZARAHEMLA is not a young country. The Mulekites have been there for almost 500 years, and the Nephites for approximately 200 years. The Nephites were "a mighty people, skilled in the arts and sciences, and whose splendor would not be eclipsed by any of the nations of Antiquity—a people once high and exalted in the scale of intelligence" ("American Antiquities," 440). This is not a culture that would have limited itself to a bridgeless travel system.
A hasty reading of the military movements in Alma 52 tempt some to limit the distance between Mulek and Bountiful to the distance an army can march in one night. In verse 22, Mormon says "Moroni and his army, by night, marched in the wilderness, on the west of the city Mulek." Moroni's beginning point is Bountiful, so some believe Mormon's description limits the distance between Mulek and Bountiful. However, reasonable people can interpret the passage differently. I frequently remind myself that Mormon's narrative is an abridgement, whose primary focus is not to identify the distance between two cities. Mormon's description allows for Moroni and Teancum to move together as a single force closer to Mulek, then separate to setup the strategy, with Moroni's army moving into the wilderness west of Mulek "by night" in order to be concealed from the Lamanites, and Teancum and his army moving to "near the seashore" by day, deliberately to be seen by the Lamanites. Mormon's use of "by night" is not intended to mark the time involved in this strategy, but to call attention to Moroni's efforts to conceal his army.