The narrator uses legend of the Mormons to explain?

Jim reminisces about the countryside in this chapter. He recounts how he used to ride his pony Dude to the post office and to give messages. During this time there are no fences, and Jim likes to ride on the roads bordered by sunflowers. He hears that the Mormons had planted the sunflowers when they were fleeing to Utah, and he therefore associates the roads with freedom.