Personal note: The Book of Mormon is a record of the people on the American continent. They came over originally from Jerusalem (one branch - another group came even earlier) about 600 B.C. If you read Ezekial 37: 16-17 the stick of Judah represents the Bible, the stick of Ephraim, the people here who brought forth the Book of Mormon. I need to find the exact reference, but in the New Testament Christ talks about "Other sheep have I which are not of this fold...." Before his ascension but after the crucifixion, Christ also visited the people here on this continent. There are stories of "Quozecoatal" (sp?) also known by other names, but all referring to the Great While God who was to return.
Ther is actually quite a bit of archeological evidence which does suggest that some of the native american, as we call them, are actually the decendants of hebrews, and also phonecians, from during the time of Soloman. Whether or not the book of mormon is their book is rather questionable though, I think, especially since it was not known among native americans.
In South america, the tribes of indians that were first encountered by europeans, who brought the word of God to the new world (the great white god), practiced rituals very similar to the pagan religions of phonecia. Likeise many early native indian religions kept customs and rituals strikingly similar to hebrew and phonecian customs and religious rituals.
The hebrews spread themselves across all of the continent, all the way into Russia and china, into Africa etc. This is undeniable. So when Jesus mentions 'others not of this fold, he is likely referring also to these. but undoubtedly he is also referring to the lost people that ventured overseas in search of treasure for King Soloman. and it is mentioned in the bible, yes, that some were lost at sea.
try
www.s8int.com I think that is the url, they have quite a bit of info there they have collected.