Alma 22:27

And it came to pass that the king sent a proclamation throughout all the land, amongst all his people which was in all his land, which was in all the regions round about, which was bordering even to the sea, on the east, and on the west, and which was divided from the land of Zarahemla by a narrow strip of wilderness, which ran from the sea, east, even to the sea west, and round about on the borders of the sea shore, and the borders of the wilderness which was on the north, by the land of Zarahemla, through the borders of Manti, by the head of the river Sidon, running from the east towards the west; and thus were the Lamanites and the Nephites divided.

The king sent a message throughout all the land to all his people. His land reached all the way to the sea on the east and on the west. It was divided from the land of Zarahemla by a narrow strip of wilderness. This strip ran from the sea on the east to the sea on the west. It went around the borders of the seashore and the borders of the wilderness on the north by the land of Zarahemla. It went through the borders of Manti by the head of the river Sidon. It ran from the east toward the west. This is how the Lamanites and the Nephites were divided.

Then the king sent out a proclamation throughout his entire kingdom—all the territory that stretched from the eastern sea to the western sea, divided from Zarahemla by a narrow strip of wilderness that ran from the east sea to the west sea, bordered on the north by the wilderness near Zarahemla, through the borders of Manti, at the headwaters of the Sidon River, running east to west. This was how the Lamanites and Nephites were separated.