"The head of the river"

1. 1 Ne. 8: 17
     17 And it came to pass that I was desirous that Laman and Lemuel should come and partake of the fruit also; wherefore, I cast mine eyes towards the head of the river, that perhaps I might see them.
2. Alma 22: 27, 29
     27 And it came to pass that the king sent a proclamation throughout all the land, amongst all his people who were in all his land, who were 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 seashore, 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.
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     29 And also there were many Lamanites on the east by the seashore, whither the Nephites had driven them. And thus the Nephites were nearly surrounded by the Lamanites; nevertheless the Nephites had taken possession of all the northern parts of the land bordering on the wilderness, at the head of the river Sidon, from the east to the west, round about on the wilderness side; on the north, even until they came to the land which they called Bountiful.
3. Alma 43: 22
     22 Behold, now it came to pass that they durst not come against the Nephites in the borders of Jershon; therefore they departed out of the land of Antionum into the wilderness, and 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.
4. Alma 50: 11
     11 And thus he cut off all the strongholds of the Lamanites in the east wilderness, yea, and also on the west, fortifying the line between the Nephites and the Lamanites, between the land of Zarahemla and the land of Nephi, from the west sea, running by the head of the river Sidon—the Nephites possessing all the land northward, yea, even all the land which was northward of the land Bountiful, according to their pleasure.