Mormons: If the Nephites and Lamanites lived in Meso- America, how did the gold plates end up in New York?

Mormons colleagues have told me that the ancient Lamanites and Nephites lived among the Maya and Aztec, yet Joseph Smith dug up the gold plates, which later became the Book of Mormon, in upstate New York. How did Moroni end up so far away from his home?