While Mormon's style of writing seems to be annalistic, that is he seems to be listing what happens year by year, Mormon notes in a number a verses chronicling the 46th year how the Nephites departed into the land northward and spread to exceeding great distances, and how they multiplied and spread to cover the face of the whole earth (see Helaman 3:3,4,5,8). For all this to happen and for the knowledge of it to return to the record keeper Helaman in one year would be remarkable. Either Helaman or Mormon seems to be taking some liberties with the annalistic protocol, or the distances involved here were not that great. [Alan C. Miner, Personal Notes]