Alma baptized in its waters. Armies crossed it multiple times in a single battle. Hills and valleys flanked its banks. The cities of Zarahemla and Gideon were positioned on opposite sides of its course. Two groups—the people of Nephi and the people of Zarahemla (the Mulekites)—shared its basin. A third group—the Lamanites—often invaded its borders and attempted to move north for their own strategic reasons. The dead from the resulting wars were unceremoniously thrown into its waters. Nearby wilderness areas provided hiding places for the Gadianton robbers to swoop down and plunder in its lowlands. And the final battles leading to the demise of the Lamanite and Nephite civilizations began near its edge and ended at Cumorah. All this and more took place along the river Sidon—the river that is central to the Book of Mormon story and a key to the Book of Mormon geography.

The river Sidon is the only named river in Mormon’s abridgment of the Nephite record. And there is only one watercourse within the heartlands of the peninsula of Baja California that could be considered the river Sidon—the Rio San Ignacio. Within minutes of our initial scrutiny of Baja California as a promising location for the Book of Mormon lands, we became cautiously aware we had only one candidate river. Impressively, this one river is located where the river Sidon needs to be situated—between the area on the peninsula identified as the narrow neck of land and the narrow strip of wilderness, precisely where Mormon places the river Sidon in his geographical narrative (Alma 22:27–34). Lehi’s family journeyed from a land that had only one major river—the river Jordan—and Egypt and several other countries have only one river of consequence.

Having only one candidate for the river Sidon allowed us to confidently move ahead and match other Book of Mormon locations to Baja California. We soon realized, however, that identifying the river Sidon was only the first step, and numerous geographical features associated with this important river course in the Nephite record would also need to match. Rivers do not exist in isolation—they are surrounded by other physical features, such as mountains, hills, valleys, banks and seas that influence the direction of their course. And rivers require a source for the water flowing along their passage to somewhere else—water that has a direction as well as a breadth and a depth. And then there are the human activities in nearby settlements and the traditional roles of rivers as defense barriers and political boundaries, along with being sources of water for people,
flocks, herds and agricultural fields. There are numerous references scattered among the chapters of the book of Alma describing activities along the river Sidon, its physical features and its crucial role in the ongoing Book of Mormon story. We soon discovered there are more details in the Book of Mormon describing the site and situation of the river Sidon than any other geographical feature.