In the Footsteps of Limhi's Expedition

The route that Limhi's expedition took when they tried to find Zarahemla but found the Land of Desolation instead.*

Sierra de las Minas, Guatemala

I think I know why "the small number of men" that Limhi sent out in search of Zarahemla got lost. The Nephites wanted help from Zarahemla to escape bondage from the Lamanites but "the king of the Lamanites set guards round about the land, that he might keep the people of Limhi in the land, that they might not depart into the wilderness" (Mosiah 19:28). 

For this reason, they were unable to leave the normal way, which was to head through the pass in the narrow strip of wilderness, north of the Land of Nephi. So they decided to head south, away from the guards then turn west until they found the source of the River Sidon then follow that down to the City of Zarahemla. 

Chixoy River, Guatemala (AKA Rio Negro, or Rio Salinas)

However, when they reached the top of the mountain they saw two rivers. (See the dot in the above illustration.) One flowed north then turned due east, the direction from which they had just come. The other flowed northwest. 

They knew that Zarahemla was northward from Nephi so they picked the wrong river, followed it all the way to the mouth where there are plenty of lagoons - a "land of many waters" - and found the land where the Jaredites' final battle had occurred. They returned via the same route with the Jaredite records in their possession.

The "pantanos" of Vera Cruz and Tabasco is the land of many waters.

Mosiah 21: 25-27 Now king Limhi had sent, previous to the coming of Ammon, a small number of men to search for the land of Zarahemla; but they could not find it, and they were lost in the wilderness. 

Nevertheless, they did find a land which had been peopled; yea, a land which was covered with dry bones; yea, a land which had been peopled and which had been destroyed; and they, having supposed it to be the land of Zarahemla, returned to the land of Nephi, having arrived in the borders of the land not many days before the coming of Ammon. 

And they brought a record with them, even a record of the people whose bones they had found; and it was engraven on plates of ore.

Model of Kaminaljuyu

The majority of Mesoamerican/Book of Mormon scholars believe the city of Nephi was Kaminaljuyu (Guatemala City). But I'm not convinced. Mainly, because the city of Kaminaljuyu was a mature city, established almost a thousand years before the time when Nephi arrived with "all those who would go with [him]" after departing into the wilderness to flee from his brothers around 575 BC. (2 Nephi 5:5)

It makes no sense for a group of newcomers to waltz in to a big city and say, "We're here to rule over you and show you how to build a temple and make swords and stuff." Instead of Kaminaljuyu, they found a remote valley with either no inhabitants or people who welcomed them to their small community. 

Motagua River valley, El Progresso department, Guatemala

I believe that valley was the upper Motagua River valley. The city of Nephi was nestled in the valley south of the Sierra de las Minas, which along with the Sierra de Chuacus are "the narrow strip of wilderness, which ran from the sea east even to the sea west." Nephi's temple was built on a hill and the tower next to it gave them a commanding view of Shilom across the valley and Shemlon further downriver towards the east in the same river valley.

The city of Nephi was abandoned to the Lamanites when Mosiah and his people migrated to the land of Zarahemla around 200 BC. It was reclaimed again by Nephites when Zeniff and his people went back and struck a deal with the Lamanites so they could re-settle there in 121 BC. 

This is another reason why the city of Nephi can't be Kaminaljuyu. When Zeniff arrived, the Lamanite king "commanded that his people should depart out of the land, and [Zeniff] and [his] people went into the land" to possess it. I can't imagine any Lamanite king commanding thousands, possibly tens of thousands, of inhabitants in Kaminaljuyu to leave in order that a handful of Nephites could settle there.

On the way to the mountain top via a tributary of the Motagua River

Recap: During Limhi's time, his expedition headed south, then west, up the Motagua River until they reached the ridge overlooking the Grijalva and Chixoy watersheds. (See the spot in the above illustration.) The Chixoy flows north then due east before it loops around and heads north to become the Usumacinta (River Sidon). The Chixoy appeared to be the wrong river because it headed the wrong direction from their vantage point. The Grijalva looked more promising so they followed it - the wrong river.

Sources:
* My map above uses the position of the Grijalva as it was 2000 years ago. Read: Wandering River by Kirk Magleby