The Mantaro River Loop Where Moroni Battled Zarahemna

A map of Central Peru, showing Lima and Pachacamac (Zarahemla) and the area of Moroni’s battle with the Lamanites in 74 B.C. around the hill Riplah (Huancas)

In the area shown on the map above as the Mantaro River, Huancas and Huaripampa, lies an area where the Mantaro River makes a large loop, providing the unique features that Mormon describes in Alma 43 regarding the battle between Moroni and his Nephite army and Zarahemnah and his Lamanite army.

A satellite view of this loop in the Mantaro River north of the area that later is changed and the Manaro runs in a series of curves back north and to the east and into the Apurimac River as it does today

In 74 B.C., just after Moroni was appointed chief captain (Alma 43:16) and took charge of the Nephite Army at the age of 25, the Lamanites came into the borders of Jershon under the command of Zerahemnah. However, seeing how under Captain Moroni the Nephites had been armed with breastplates and shields, wearing body armor for the first time, the Lamanites were “exceedingly afraid…notwithstanding their number being so much greater” (Alma 43:22) and departed out of the land of Antionum into the wilderness. They took their journey round about in the wilderness, away by the head of the river Sidon, that they might come into the land of Manti and take possession of the land; for they did not suppose that the armies of Moroni would know whither they had gone (Alma 43:22).
    However, the Lord informed Alma who sent word to Moroni about the Lamanite plans and Moroni headed for the Land of Manti where he prepared to intercept them. There, where the Sidon River made a loop around a valley, west of a hill called Riplah, Moroni set his trap with his army on both sides of the river on the two west sides of the same river.

Mantaro River makes a loop through the valley to the west of Huaripampa in the Province of Jauja and Region of Junin, about 110 miles east of Lima (Pachacamac), and about 14 miles west and south of Huancayo, within the Huancas Valley, located about 20 miles to the west of where the Andes sloped down into Amazonia

  

This valley is flatter toward the north and east, but hilly in the center with broken ground to the south and west. The river along the east loop runs past a cliff-like hill, which not only forces the river to flow around it, but also any large force entering the valley from the northeast, around a series of hills that rise up to oversee the valley. Along the western loop, beyond the river where Moroni would have secreted the force he directly commanded, are low, rolling hills, that effectively block any line of site from the eastern loop of the river.
    Today, the city of Huaripampa (Quechua for Vicuña Valley) lies about five and a half miles south of the city of Jauja in the Central Highlands about 110 miles east of Lima. This 11,000-foot high plain stretches around the Mantaro River, which flows along the western ridge of hills. In the west area of the valley, beyond a large hill, the Mantaro River makes this large loop to the south, where the two west sides of the river run parallel to each other about a mile apart, just south of a hill along its western side and a valley in between.
    While this may not be the site of Moroni’s battle with the Lamanites, the terrain and loop of the otherwise straight running Mantaro River (prior to where it now turns to the east to run northward) does fit the scriptural descriptions and provides us at least with an example of the stratagem Moroni employed against the Lamanites who were heading toward Zarahemla in the west, across a series of flattened ridges and low hills.

The Lamanites came up on the north of the hill, where a part of Moroni’s army was concealed, and as the Lamanites had passed the hill Riplah, and came into the valley and began to cross the river Sidon, the army which was concealed on the south of the hill, which was led by a man whose name was Lehi, marched forth and encircled the Lamanites about on the east in their rear

Today, this area or district is characterized by the pre-Inca archaeological remains of Canchahuanca, Quinlluy and Punpunaj. However, in 74 B.C. there was little in the area other than Jershon and Manti as well as other smaller Nephite settlements (Alma 43:26) from which Moroni recruited additions to his army.
    These hills and mountains around this valley are of compacted tuff and volcanic rock, ejected by an explosive volcanic eruption. Since tuff is usually thickest on the downwind side of the vent or on the side of the vent where the blast was directed, it seems likely the hills and mountains around this valley resulted from close by eruptions.
    If this is the area where Moroni’s battle took place, then the hill Riplah was most likely a volcanic vent or dome. Definitely this western slope of the Andes in Central Peru where this valley and surrounding hills are located are those described by the Mineralogisch-Petrographisches Institute in Heidelberg (Liuis Fontbote, et al., Stratabound Ore Deposits in the Andes, Springer-Verlag, Berlin, 1990).

Using the numbering system in the map above this images: (1) When the Lamanites rounded the hill Riplah, (2) they entered a pass between high mountain cliffs, (3) then came to a low rolling hill area and crossed the Mantaro River, (4) the view of Moroni toward the advancing Lamanites crossing the low-lying hills, where Lehi would have attacked from the west and the Lamanites fled toward the river (foreground) behind which Moroni waited

Of this battle instigated by the Lamanite leader, Zarahemnah (Alma 43:5), we find that “Moroni caused that his army should be secreted in the valley which was near the bank of the river Sidon, which was on the west of the river Sidon in the wilderness. And Moroni placed spies round about, that he might know when the camp of the Lamanites should come…he divided his army and brought a part over into the valley, and concealed them on the east, and on the south of the hill Riplah…the remainder he concealed in the west valley, on the west of the river Sidon, and so down into the borders of the land Manti” (Alma 43:27-28,31-32).

Moroni’s view from the West Bank of the western loop of the Mantaro River looking eastward across the valley toward where the Lamanites would come

Once Moroni divided and placed his army upon both western banks of the Sidon River and toward the south, he settled in and waited, relying on his spies to tell him specifically where the approaching Lamanites, who “came with their thousands” (Alma 43:5), would enter the Valley. As Mormon states it: “the Lamanites came up on the north of the hill, where a part of the army of Moroni was concealed” (Alma 43:34), with an army that was more than double the size of Moroni’s force (Alma 43:51).
    When the Lamanites entered the valley, they were attacked in the rear by Lehi and his Nephite force, which caused the Lamanaites to stop their movement across the valley and do battle. Unbeknown to the Lamanites, the army concealed in the south advanced and attacked. Suffering severe casualties by the better armed and protected Nephites, the Lamanites fled toward the river on the opposite side of the valley; however, Moroni advanced across the river and attacked the fleeing Lamanites, who were now effectively surrounded.
    Again, while this loop in the Mantaro River, the hill to the northeast and the valley in the west matches the description Mormon describes, there is no way of knowing if this is the actual site. However, it certainly meets all the criteria and, if nothing more, picturesquely describes the battle between Moroni and Zarahemnah.