Given the criteria that the river Sidon has a singular head, or source, and that it flows in a southwest direction, we propose the Rio San Ignacio in Baja California as a plausible candidate for this unique and central river in the geography of the Book of Mormon. The Rio San Ignacio has a large lagoon at it’s head that is fed by several springs. The river is surrounded by four wilderness areas and eventually empties into a large embayment on the Pacific Ocean to the west. Although it meanders along its course, the general flow of the river is in a southwest direction. There are prominent hills along its rather high banks that match the detailed geographical descriptions of hill Riplah and hill Amnihu. See the sections on The Head of the River Sidon; Wilderness of Hermounts; Crossing the River Sidon; Hills, Valleys and Banks; Bodies are Cast into the River Sidon; and City of Zarahemla and the City of Gideon in our main article, An Approach to the Geography of the Book of Mormon.