Historical background: Lehi's trail. Lehi leaves Jerusalem and enters the "wilderness" in the borders of the Red Sea. One of the unasked questions about Lehi's flight is why he chose that direction. Assuming that they were to eventually build and board a ship, why didn't Lehi flee West to the Mediterranean?
The easy answer is that Lehi was fleeing, and to go in virtually any other direction led him into thicker civilization, and possibly into the waiting arms of enemies. Toward the desert was the sure path of escape, a route which had been an historical option for those fleeing difficulties in their cities (Nibley, Lehi in the Desert p. 82).
Along the border of the Red Sea, on the Eastern side, was a well known and traveled merchant trail. Even though it was well known, it was not likely to have held high traffic, and is likely that Lehi used this trail, and just as likely that he was familiar with it. In none of the verses dealing with the early part of the journey is their any indication that they did not know where they were going, or how they were to survive as they went there.
Three days into their journey, they stop in a valley with a river. In the borders of the Red Sea there are several wadis which could have been blessed with water during the rainy season. As noted earlier, the fact that water was present helps to date the time of their arrival to the rainy season, as the river was likely not there at other times.
Socio-Cultural information: Naming places When Lehi finds the river in the valley, he names it for Laman. In doing so he followed oriental custom in naming bodies of water, and other land features. It was not/ is not unusual for lands and features to have multiple names in different places (and likely for many to have been forgotten) (see Nibley Lehi in the Desert p. 88-89).
Religious significance: Lehi's altar Lehi was a prophet called of God, and directed by that God to leave his home. Lehi clearly understood the reason for his flight to be the threats on his life. Notwithstanding that he had left his land of inheritance, his home, and his worldly goods, he nevertheless erected an altar to give thanks to the Lord for his deliverance. Notice that there are no known actual attempts on his life, and that the sole real evidence that Lehi has that he has been led to salvation is the word of the Lord. Nevertheless, it is sufficient for him, and he gives thanks for salvation from an event of which he really only knows by revelation.
Lehi builds an altar of stones, which was a typical Arab/Hebrew wilderness altar. Building an altar of stones is, on the one hand, due to exigency as there were likely few other building materials available. However, the altar of stones is probably more significant than that. Why was the sacrificial site not a pit ringed by stones? Why was it not simply a brush pyre?
Early Israelite worship understood "high places" to be of particular religious significance. Moses receives his epiphany on the Mount. The elevation of stones probably served two purposes, the first of which was to create a miniature "high place" which through its symbolic elevation provided a sacred location. The second was that the use of stones connected the altar to the natural order, and built a symbolic miniature sacred mountain upon which the offer of sacrifice would be effective.
The next point of interest concerning Lehi's altar is that he built it in the first place. Lehi traced his genealogy through Joseph, not Levi, and therefore was not a Levite, and therefore not one of the line of priests who should be offering sacrifices. In addition to the obvious ability of the Lord to provide whatever priesthood is necessary for his prophets, it is also probably that Lehi was engaged in sacrifices which did not require Levites. Indeed, from what can be discerned of noted sacrifices in the Book of Mormon, they were not those which would have required a Levite. Clark Goble discusses the possible nature of the Law of Moses in the New World:
"It may be that they formed a rather unique version of the Law of Moses - one without the sacrifices of the Levites. We have the sacrifice in Mosiah 2:3 fulfilling Ex 13:11-13; Ex 22:29-30; and Dt 15:19-23. But this is a sacrifice that doesn't require Levites, as I understand it. (It is also a very Christological symbol, fitting in with their anticipation of the savior) All the other references to sacrifice in the Book of Mormon refer to the sacrifice of the savior, with the exception of thank- offerings.
1 Ne. 5:9 And it came to pass that they did rejoice exceedingly, and did offer sacrifice and burnt offerings unto the Lord; and they gave thanks unto the God of Israel.
These thank-offerings also didn't require a Levite. (Note the parallelism ephasizing that the offerings are thank-offerings) See for example Judges 6:20-27; Judges 13:19-20; 1 Samuel 14:34-35 or 1 Samuel 9 where a prophet, like Lehi, is present." (Clark Goble, "Lehi's Authority" 2 June 1996, Scripture-L).