The following comes from: “A Brief History of the Limited Geographic View of the Book of Mormon” by John A. Tvedtnes
Finally, we must return to the question of Cumorah. Many Book of Mormon readers automatically assume that the hill near Palmyra, New York, must be the same hill called Cumorah in the Book of Mormon, since Mormon hid plates in the hill of that name and Moroni disclosed the location of plates to Joseph Smith some fourteen centuries later. THERE IS NO REAL LOGIC BEHIND THIS. Mormon wrote,
And it came to pass that when we had gathered in all our people in one to the land of Cumorah, behold I, Mormon, began to be old; and knowing it to be the last struggle of my people, and having been commanded of the Lord that I should not suffer the records which had been handed down by our fathers, which were sacred, to fall into the hands of the Lamanites, (for the Lamanites would destroy them) therefore I made this record out of the plates of Nephi, and hid up in the hill Cumorah all the records which had been entrusted to me by the hand of the Lord, save it were these few plates which I gave unto my son Moroni. (Mormon 6:6)
From this, it is clear that Mormon hid in the hill Cumorah “all the [Nephite] records except the abridgment plates, which he gave to his son Moroni. As he was adding his own work and testimony to those abridgment plates, Moroni frequent spoke of his intention to hide the plates, but he never names the place where he hid them. After the last great Nephite/Lamanite struggle at the hill Cumorah in ca. A.D. 385 (Mormon 6:5), Moroni was on the run from the Lamanites and his last entry into the abridgment record notes that the 420th year had passed (Moroni 10:1). HE HAD MORE THAN ENOUGH TIME (35 years) TO TRAVEL FROM SOUTHERN MEXICO TO UPSTATE NEW YORK, where he deposited the plates and later revealed their location to the prophet Joseph Smith.
Our Response: It is ILLOGICAL to believe Mormon or Moroni would go to the final battle without having first secured the urim and thummim, the breastplate, and the plates for Joseph to find. They were quite aware of the prophecies that said they should PERISH SUDDENLY:
16 For those who shall be destroyed shall speak unto them out of the ground, and their speech shall be low out of the dust, and their voice shall be as one that hath a familiar spirit; for the Lord God will give unto him power, that he may whisper concerning them, even as it were out of the ground; and their speech shall whisper out of the dust.
17 For thus saith the Lord God: They shall write the things which shall be done among them, and they shall be written and sealed up in a book, and those who have dwindled in unbelief shall not have them, for they seek to destroy the things of God.
18 Wherefore, as those who have been destroyed have been destroyed speedily; and the multitude of their terrible ones shall be as chaff that passeth away — yea, thus saith the Lord God: It shall be at an instant, suddenly. (2 Nephi 26)
10 And these are the words: Behold, I perceive that this very people, the Nephites, according to the spirit of revelation which is in me, in four hundred years from the time that Jesus Christ shall manifest himself unto them, shall dwindle in unbelief.
11 Yea, and then shall they see wars and pestilences, yea, famines and bloodshed, even until the people of Nephi shall become extinct— (Alma 45:10-14)
5 And he said unto them: Behold, I, Samuel, a Lamanite, do speak the words of the Lord which he doth put into my heart; and behold he hath put it into my heart to say unto this people that the sword of justice hangeth over this people; and four hundred years pass not away save the sword of justice falleth upon this people.
9 And four hundred years shall not pass away before I will cause that they shall be smitten; yea, I will visit them with the sword and with famine and with pestilence.
10 Yea, I will visit them in my fierce anger, and there shall be those of the fourth generation who shall live, of your enemies, to behold your utter destruction; (Helaman 13)
Tvedtnes also ignores official LDS canon and history; Book of Mormon witnesses, angels, and Joseph Smith who identified the hill in Palmyra as “The” Hill Cumorah, land of the final battle. See Cumorah