Mormon was faithful in executing Ammaron's command. Ten years prior to 345 AD, at the age of 24, Mormon took the large plates of Nephi from among a huge collection of other records and began to record his history. Elder Anthony W. Ivins said, "It will be observed that at this time only the plates of Nephi were removed from the hill Shim, by Mormon." (Conference Report, Apr. 1928, p. 12) Over thirty years later, after 375 AD, Mormon decided it was time to take possession of all the other records (Mormon 4:23). He was their custodian until just before the great and last battle, 385 AD, when he placed them securely in the hill Cumorah (see Mormon 6:6).