Let’s Be Honest About This

There is an area in Mesoamerica (or Middle America), a region and cultural area in the Americas, extending from approximately central Mexico to Belize, Guatemala, El Salvador, Honduras, that has, for some time now, referred to as a narrow area called the Isthmus of Tehuantepec, and represents the shortest distance between the Gulf of Mexico and the Pacific Ocean. Prior to the opening of the Panama Canal, it was a major shipping route known simply as the Tehuantepec Route. The name is taken from the town of Santo Domingo Tehuantepec in the state of Oaxaca, which was derived from the Nahuatl (Aztec language) term tecuani-tepec, meaning “jaguar hill.”

Meso or Middle America

According to Edmond Otis Hovey in 1907, the narrowest point of the isthmus is 200 killometers across, or 120 miles, from gulf to gulf (“The Isthmus of Tehuantepec National Railway,” Bulletin of the American Geological Society, Vol 39 (1), 1907, pp78-91); however, it actually measures currently at 144 miles by the Mexican Government, measuring access by foot traffic in the inaccessible area before modern conveniences. It should be noted that a railroad, involving four different attempts at completion covered 130 miles, and a final railroad, now in service, ended up covering 191 miles from coast to coast.
    The Sierra Madre de Oaxaca breaks down at this point into a broad, plateau-like ridge to form the Chivela Pass, whose elevation, at the highest point reached by the Ferrocarril Transistmico railway was 224 meters, or 735 feet. The Sierra Madre de Chiapas mountains resume to the south, so geographically the isthmus divides North America from Central America. The southern edge of the North American tectonic plate lies across the Motagua Fault in Guatemala, so geologically, the division between North America and Central America (on the Caribbean Plate) is much farther south than the isthmus of Tehuantepec.
    The northern side of the isthmus is swampy and densely covered with jungle, which has been a greater obstacle to railway construction than the grades in crossing the sierra.
    The Selva Zoque (Zoque Forest), which includes the Chimalapas rain forest, is the largest tract of tropical rainforest in Mexico, and is located in the eastern part of the mountain range that forms the spine in the eastern-central region of the Isthmus, bordering on Veracruz to the north, Oaxaca to the west and Chiapas to the east. It is an area of great ecological importance and holds the majority of the terrestrial biodiversity in Mexico. The forest forms a vital biological corridor between North and Central America, with a rugged terrain that includes a complex mixture of forest types at different levels and covers about one million hectares. The forest also contains the headwaters of five hydrological systems, including the El Corte River watershed, the Negro River watershed, the Uxpanapa River watershed and the Coatzacoalcos River that flows into Veracruz's southern wetlands and the Gulf of Mexico; and the Espiritu Santo River watershed which supplies the lagoon system to the south in the Pacific Ocean.

The narrower area of the isthmus, and the gap in the Sierra Madre, allow the trade winds from the Gulf of Mexico to blow through to the Pacific. Normally, these winds are not particularly strong, but periodically, a surge of denser air originating from the North American continent will send strong winds through the Chivela Pass and out to the south over the Gulf of Tehuantepec the Pacific coast. This wind is known as the Tehuano.
    Since the days of Hernân Cortés, the Tehuantepec isthmus has been considered a favorable route, first for an interoceanic canal, and since the 19th century for an interoceanic railway. Its proximity to the axis of international trade gives it some advantage over the Panama route; however, because the Isthmus of Panama, was significantly narrower, making for a shorter traversal, the canal was placed there even though it is further from the natural trade routes.
    It is important to note that soon after the day the Book of Mormon was first published, there have been those, specifically beginning at BYU, who proposed that the “narrow neck of land” of the scriptural record was this Isthmus of Tehuantepec.

Sahagun’s Manuscript and map, showing almost no indentation at the Isthmus of Tehuantepec area—which would have been an unobservable point in the time of Sahagun

However, it should also be noted that in the scriptural record, this “narrow neck of land” was so prominent to the inhabitants of the Land of Promise that it was a noticeable, and therefore, a point of unquestioned knowledge, that this terrain feature was understood by the early inhabitants of the area, namely, the Nephites who wrote about it as a specific point of geography, first described by Mormon as “a small neck of land between the land northward and the land southward” (Alma 22:32), and later as “the narrow neck which led into the land northward” (Alma 63:5). Joseph Smith translated Mormon’s writing as “a small neck” and a “a narrow neck” of land, which according to Noah Webster’s 1828 American Dictionary of the English Language, which was used in the School of the Prophets by Joseph Smith and Oliver Cowdery and others, as “neck” being “A long narrow tract of land projecting from the main body, or a narrow tract connecting two larger tracts; as the neck of land between Boston and Roxbury.” The word “narrow” is defined as “of little breadth; not wide or broad; having little distance from side to side” and the word “small” as “slender, thin, fine, little in size, slender part.”
    Now let’s apply this type of small and narrow to the location in Mesoamerica, keeping in mind the all-important point that the Nephites knew and understood this area was “small” and “narrow” strictly from line of sight available to them between 200 B.C. and 400 A.D., before aerial photography or satellite imagery. In other words, the average Nephite would have been able to tell that this area, from standing upon it, was so narrow, as to be a small neck of land, or a narrow neck of land.

A 1680 map showing one of the earliest understandings of the Tehuntepec area. Note there is little indentation and certainly no awareness of a “narrow neck of land”

A 1703 map by Guillaume de Lisle, a French cartographer known for his popular and accurate maps of the newly explored Americas. Note there is no definition of the Isthmus of Tehuantepec. To those who drew the map, the land did not suggest any specific narrowing

A 1710 map of Mesoamerica showing no indentation of other suggestion of a narrow neck of land to those who saw both coasts

A 1715 map by George Wildey of London. Again, there is little if any identation along either coast

In this 1733 map, note there is no indentation at all along the Gulf of Mexico coastline to even suggest there was a narrowing, let alone a small neck of land (numbers have reference to another topic)

Again, in this 1803 map, there is no indication of a narrow neck or even small neck, to a person on foot in the area encircled

Another map, this one 1811, showing no specific narrow or small neck of land that would have been apparent to someone in the area looking at these coastlines

Still another map, this one 1831, showing a southern coastline that could not possibly be considered a narrow neck or small neck of land to someone standing along the coast or inland

An ancient map of Mexico. Note the lack of any narrowing of the area now known as the Isthmus of Tehuantepec. In the 18^th century, this is what the area appeared to be to those who saw and drew it

In a Salt Lake Tribune article entitled "BYU and UVU scientists question research offered at a conference on the Book of Mormon," by Benjamin Wood, and dated September 5, 2017,  heartland theorist Jarom Session is quoted as saying, "Just because a theory is taught for 'generations' as fact, that alone does not make it credible or true when the observable evidence shows otherwise." We might apply that reasoning to the Mesoamerican theory of the Isthmus of Tehuantepec being the Book of Mormon "narrow neck of land." Obviously, observable evidence of these numerous ancient maps show that people in the period from the 17th to the 20th century did not see Tehuantepec as being an isthmus, let alone "narrow" or "small" as Mormon described this feature of land in the scriptural record.
    The point of all of this is simple. Before aerial photography and satellite imagery, all the maps drawn of the area now known as the isthmus of Tehuantepec do not show any indication of an indentation sufficient to suggest to a person standing on the beach, or crossing the area now known as the isthmus, that this was a “narrow” or “small” neck of land as Mormon and Moroni called it in the scriptural record. People simply did not see it as an isthmus or a narrow neck of land during these first 400 years that these maps cover, but simply as land. There is no way that this area, to the Nephites in 200 B.C. to 400 A.D. could have possibly seen this as a narrow neck or small neck of land as Mormon lists it. And if the Mesoamericanists would be honest with themselves on this issue, they would admit that this area would not have been known as such to the Nephites and could not be considered as such today relating to the Land of Promise.