Ammaron was a Nephite record keeper who took charge of the sacred records around AD 306, following a line of keepers that ran from his great-grandfather Nephi to his grandfather Nephi, his father Amos, and his brother Amos. He received the records after Amos died, when the robbers of Gadianton had spread over the whole land and none remained righteous except the disciples of Jesus Christ (4 Nephi 1:46-47).
In AD 320, constrained by the Holy Ghost, Ammaron hid up all the sacred records that had been handed down from generation to generation, that they might come again to the remnant of the house of Jacob according to the prophecies and promises of the Lord (4 Nephi 1:48-49). About the time he hid the records, he came to a boy named Mormon, then about ten years old, and told him that when he reached twenty-four he should go to the land Antum, to a hill called Shim, take the plates of Nephi, and engrave on them what he had observed concerning his people (Mormon 1:2-3).
Mormon later went to the hill as instructed, took the plates of Nephi, and made a record according to the word of Ammaron (Mormon 2:17).