For the geographical significance of these verses, see commentary for Mormon 6:2.
Hugh Nibley
“The description of how people were driven out of a land by a plague of serpents that then ‘hedge up the way that the people could not pass’ (Ether 9:31-35) may put a strain on your scientific credulity. I hasten to relieve it. Pompey the Great, we are told, could not get his army into Hyrcania because the way was barred by snakes along the Araxes, a stream that still swarms with the creatures. One of the chief philanthropic activities of the Persian magi was to make war on the snakes—a duty which must go back to a time when the race was sorely pressed by them. The Absurtitani were said to have been driven from their country by snakes, and Esarhaddon of Assyria recalls the horror and danger of a march by his army through a land ’of serpents and scorpions, with which the plain was covered as with ants.’ In the thirteenth century A.D. Shah Sadrudin set his heart on the building of a capital which should surpass all other cities in splendor; yet the project had to be abandoned after enormous expense when during a period of drought the place so swarmed with serpents that no one could live in it. It is interesting in this connection that the plague of serpents in Ether is described as following upon a period of extreme drought (Ether 9:30).” (Lehi in the Desert and the World of the Jaredites, p. 221)