In Alma 22:31, Mormon states: "the land on the northward was called Desolation, and the land on the southward was called Bountiful, it being the wilderness which is filled with all manner of wild animals of every kind, a part of which had come from the land northward for food." One might notice that Mormon apparently speaks as if the reader is familiar with the wilderness spoken of here. Indeed, the geographical phrasing is very similar to that in Ether 9:30-35. In speaking of a drought and plague of serpents among the Jaredites, Moroni says that animals and everyone did flee "towards the land southward, which was called by the Nephites Zarahemla." Then, after the drought and plague, in Ether 10:21 Moroni says "they did preserve the land southward for a wilderness to get game". Thus here in Alma 22:31, Mormon might be referring to that portion of Jaredite history and trying to tie it in with the Nephite culture. [Alan C. Miner, Personal Notes] [See Geographical Theory Maps--also those for Ether 9:30-35]
Geographical [Theory Map]: Alma 22:30 The Land Bountiful and the Land Desolation (4th Year)