The term "fountain" in the Book of Mormon has a different meaning than the most often used current English definition. It does not refer to anything that sprays water. It is used five times in direct reference to a deep pool in a river. It is used four times as a metaphor as in the "fountain of righteousness." It is used once to describe the waters of Mormon and although there is no direct reference that the waters of Mormon was a river, the usage of the phrase "waters of" allows it to be a river. If the waters of Mormon was not a river, then it would be the only use of the term "fountain" to mean something other than a deep pool in a river.

The clearest definition comes from I Nephi 3:124 [12:16], "And the angel spake unto me, saying, Behold the fountain of filthy water which thy father saw; yea, even the river of which he spake; and the depths thereof are the depths of hell." Using the grammar rule associated with "yea, even" we can see that the fountain of filthy water is a deep place in a river.

One of the uses is to describe where the river Laman empties into the sea, I Nephi 1:36 [2:9], "And when my father saw that the waters of the river emptied into the fountain of the Red Sea, he spake unto Laman, saying, O that thou mightest be like unto this river, continually running into the fountain of all righteousness." The mouth of the river, or the sea, or a lagoon, or the bay where the river empties into the sea is referred to as a fountain. This would be considered as an ultimate deep pool in the river.

What this means to interpreting the geography is that a fountain means there is a river. Also, that there is a deep spot in the river. In order to have a deep part of the river that can be distinguished and named means that there are also shallower parts of the river that defines the beginning and end of the deep portion of the river.