Summary of proposals.
This geography differs considerably from any previous model that I am familiar with. However, there are some minor correlations with the geography proposed by Stout in 1950 (Sorenson, John L. The Geography of the Book of Mormon: A Source Book. FARMS. 1992 p.186-7). See the following sections for a justification of these proposals.
1) The Jaredites traveled eastward from Sumer (Mesopotamia), to coastal China, crossed the Pacific Ocean, and landed somewhere on the coast of southern Mexico, Guatemala, or El Salvador.
2) The Nephites traveled from the area of Jerusalem, to the Arabian Peninsula, eastward across the Pacific, and landed on the Pacific coast of western Panama or southwestern Costa Rica (possibly the Diquis Delta or the Osa Peninsula). This coastal area was the land of the Nephites first inheritance.
3) The Mulekites traveled from Jerusalem westward across the Atlantic, first landing somewhere on the Gulf coast of the land northward (Mexico, Guatemala, or Honduras). Here they had some contact with the Jaredites. They subsequently migrated south to modern Costa Rica and up the Reventazon (Suerre) Valley where they established the city of Zarahemla.
4) The Isthmus of Rivas in western Nicaragua was the narrow neck of land (Map) referred to in the Book of Mormon.
5) The Central Valley (Meseta Central), combined with the upper Reventazon valley in Costa Rica, was the Book of Mormon land of Zarahemla. The Reventazon (Suerre) River was the river Sidon.
6)The Land Bountiful encompassed the plains of Guatuzos and San Carlos, northwest to the Isthmus of Rivas in Nicaragua, and southward from the San Juan River to the flanks of the Central Mountains (the Tilaran, Guanacaste, and Central ranges ).
7)The Land Desolation began at about the Nicaraguan/Costa Rican border, and went northward along the Pacific Nicaraguan coast for an unknown distance.
8) The upland area around Volcan, Panama was the Land of Nephi (Lehi-Nephi). The spring fed lakes of Las Lagunas near Volcan were the Waters of Mormon.
9) East--west extensions of the northern front of the Talamancan Mountains in Costa Rica, and their impenetrable covering of rainforest, formed the "narrow strip of wilderness" separating the lands of Zarahemla and Nephi. The main body of the Talamancan Mountain chain was the general southern wilderness of the Lamanites.
10) The majority of all the ancient ruins in southern Mexico and Guatemala were originally of Jaredite origin. These original Jaredite buildings were subsequently superimposed by later structures resulting in the imposing Mayan ruins we see today.
11) As the Jaredites did not generally occupy the land south of the "narrow neck", and assuming that number ten above is correct, it follows that all of these ruins in Mexico and Guatemala would be north of this key landmark. Therefore the Isthmus of Teuhantepec in Mexico could not be the narrow neck of land connecting the land southward and the land northward..
12) The Jaredite culture and ruins were probably patterned after early Sumerian architecture and culture. They are probably related to comparable ancient cultures in China and the far east.
13) Many of the archaeological ruins of the Jaredites and later groups were built or designed by spiritually apostate groups for idolatrous practices, and may have been used in the rites and practices of secret societies.
14) The Jaredite was the greatest civilization of the ancient world. In contrast the Nephite (as used here, Nephite will include Lamanite and Mulekite peoples) culture was smaller in size, less influential socio-politically, and insignificant architecturally. As a result, we would expect to find substantial evidences of the Jaredite civilization in the land northward (Mesoamerica), and lesser evidences of Nephite remains in the land southward (southern Central America).
15) The Jaredites constructed their public buildings of stone, while the Nephites built the majority of their buildings of wood . As a result, only faint traces of Nephite architecture would remain (in comparison to Jaredite ruins).
The following material will attempt to offer evidence and arguments which will hopefully justify these basic assumptions and proposals.