In Frost's "The Mountain," how does she frame the poem? How does she use the major themes of barriers, isolation, alienation, and distance in this poem? With this in mind, what does it signify as a whole?

The poem is structured as first-person narration, alternating with dialogue. The narrator observes and comments on the mountain in front of him for the first 18 lines. His observations establish the frame for the longer dialogue (most of Lines 19–113) between the narrator and the ox-cart driver who comes along the road and conclude the poem with its final 3½ lines. The narrator is a stranger, it is revealed, and the driver a local resident.
The mountain is a physical barrier in many ways because of its sheer size (“That thing takes up all the room”) and its blocking out aspects of the terrestrial landscape and the sky (“I missed stars in the west, / Where its black body cut into the sky”). Distance is relative, as the stranger has come looking for a particular town, apparently still a few miles away: “the town of my sojourn, / Beyond the bridge, was not that of the mountain . . . .” The area’s settlements are isolated, not even constituting a proper town. To reach his destination, the driver tells him, the approach is five miles back, and that climbing up, one would reach a spring: “a good distance down might not be noticed / By anyone who’d come a long way up” (emphasis in original).
Both the narrator and the driver are alienated from their environment, but in different ways. From the dialogue, it becomes clear that the driver experiences the push-and-pull of belonging and alienation from his home environment. While he has lived around the base of the mountain, he has not explored it fully by climbing up to its top. He has heard “from those who have been up” that there is not quite a proper path . The juxtaposition of familiarity and ignorance is well represented by his views on the spring water, which is “warm compared with cold, and cold compared with warm.” The narrator, however, has a more romantic view of the mountain’s potential, speaking of how things should be: “There ought to be a view around the world/ From such a mountain . . . .”
The distance and alienation between the narrator and the ox-cart driver are extreme. These contrasts fit well with the poem's overall significance, based in the theme of familiarity as a paradox—we know least about that with which we are most familiar. The driver’s curiosity is not as strong as his acquiescence to his situation. He seems, even, to enjoy knowledge about things secondhand more than doing them himself, as he relates to the narrator what he himself has only heard:

There’s a brook
That starts up on it somewhere—I’ve heard say
Right on the top, tip-top—a curious thing.

Further down, he also speaks of hearsay: “One time I asked a fellow climbing it / To look and tell me later how it was.”
The narrator, who it seems wants first-hand experience, actually seems content just to hear the driver’s stories and ultimately is cut off even from those, as the driver abruptly moves along: “What, I did not hear. / He drew the oxen toward him . . . and was moving.”
Counter-posed to the distance between the men, then, is familiarity of a certain kind. They both seem to derive pleasure from the telling of the thing; the narrator is rather verbose, while the driver appreciates words: “all the fun’s in how you say a thing.” This leaves open the possibility that his stories were just that, and he may well have scaled the mountain after all.
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