According to Hugh Nibley, in Arabia it is this practice of following "the more fertile parts of the wilderness" (see 1 Nephi 16:16) that alone makes it possible for both men and animals to survive. Cheesman designates as "touring" the practice followed by men and beasts of moving from place to place in the desert as spots of fertility shift with the seasons. [Hugh Nibley, Lehi in the Desert, F.A.R.M.S., p. 59]
“We Did Travel in the More Fertile Parts of the Wilderness”
After showing a number of photographs of the Palestinian Desert, Hugh Nibley points out that there are long stretches of fertility in the desert. Bushes grow over underground water channels or aquifers. Sometimes in the photographs you will see them running as far as a hundred miles, and you follow them. In the wilderness Nephi said, "We survived by keeping to the more fertile places of the wilderness" (see 1 Nephi 16:15-16). Well, there are more fertile places of the wilderness, and you stick to them. The Arabs survive by following these places where the underground water produces vegetation. [Hugh W. Nibley, Teachings of the Book of Mormon, Semester 1, p. 120]
1 Nephi 16:15 Slaying food by the way, with our bows and our arrows and our stones and our slings ([Illustration]): Nephi Hunting [Gary E. Smith, Verse Markers, Book of Mormon, Vol. 1, p. 3]
“The More Fertile Parts of the Wilderness”
After describing how they kept in "the most fertile parts of the wilderness," Nephi states the following about the next section of their journey:
And it came to pass that we did travel for the space of many days, slaying food by the way, with our bows and our arrows and our stones and our slings. And we did follow the directions of the ball, which led us in the MORE fertile parts of the wilderness. (1 Nephi 16:15-16; emphasis added)
According to Potter and Wellington, it is intriguing that the Book of Mormon account of these different parts of the journey conforms to the actual fertility of the lands along the main branch of the Frankincense trail as it proceeds through the "most fertile" Qura Arabiyyah, and then through the "more fertile" parts south-southeast from Medina to Bishah.
Just south of Medina (Yathrib) there were two branches of the trail that Lehi could have taken:
(1) The more westerly one followed the Wadi al-Aqiq in a southwesterly direction to Mecca, and then in a southeasterly direction to Bishah. This branch of the trail would have provided Lehi with a milder climate and established trails, however the coastal mountain route was rocky and not as well suited for camels. The mountains in this part of Arabia are called the Asir, which means "difficult" "because of the impact of the terrain on travel."
(2) The alternative route, or more easterly route, traveled on a general south-southeast bearing, skirting the lava fields and staying in the Arabian shelf desert. Frankincense trail expert Nigel Groom believes that this route was the main one for reasons of topography. After leaving Medina, this easterly main trail exited the mountains and into the flatlands. This inland route through the flat desert plain, called the Arabian shelf, had its own problems, yet these were more than outweighed by the benefit of good footing for the camels.
The Book of Mormon text seems to favor the more easterly main trail. That route's exit from the mountains would explain why Nephi no longer makes any mention of "the borders near the Red Sea." Furthermore, as one traveled on this trail south of Medina, farms became fewer and farther between. Potter and Wellington write of using Tactical Pilotage Charts (TPC) which indicate areas of cultivation in order to verify this information. Between al-Ula and Medina ("the most fertile parts"), there were 25 places marked. On the average, there was a cultivated area every 11 miles. However, from just south of Medina past Turbah and on to Bishah ("the more fertile parts"), the land was markedly less fertile (see illustration). There were only 6 areas labeled "cultivation" on the charts, an average of roughly one cultivated area every fifty miles. Thus hunting would shifted from a nicety to more of a necessity, a fact alluded to in the text.
The entire course from Medina to Bishah (the "more fertile parts") would have been approximately 350 miles. Groom estimates that an incense caravan would have taken fifteen to eighteen days to complete this part of their journey. Lehi's family would have traveled at a slower pace. Nephi notes that they traveled "for the space of many days." [George Potter and Richard Wellington, Discovering the Lehi-Nephi Trail, Unpublished Manuscript, 2000, pp. 127-129]
1 Nephi 16:15-16 And it came to pass that we did travel for the space of many days . . . in the more fertile parts of the wilderness ([Illustration]--Potter Theory): The More Fertile Parts. [George Potter and Richard Wellington, Discovering the Lehi-Nephi Trail, Unpublished Manuscript, 2000, p. 140]
1 Nephi 16:15-16 And it came to pass that we did travel for the space of many days . . . in the more fertile parts of the wilderness ([Illustration]--Potter Theory): By the time the family reached Turbah the terrain had changed. Fertile rest stops were much fewer and further apart. [George Potter and Richard Wellington, Discovering the Lehi-Nephi Trail, Unpublished Manuscript, 2000, p. 141]
1 Nephi 16:15-16 And it came to pass that we did travel for the space of many days . . . in the more fertile parts of the wilderness ([Illustration]--Potter Theory): Map Showing the Trail Taken by the Family through Arabia. [George Potter and Richard Wellington, Discovering the Lehi-Nephi Trail, Unpublished Manuscript, 2000, p. 260]