Bell's Gap is a place name, and the poem treats it as a landscape where nature and history both slow down and settle. It begins with the image of a woodpecker and its "speckled woods," then watches the forest burn down in November colors, "weathering novemberly down to embers." The woods aren't literally on fire; the autumn leaves glow and fade like a dying fire.
The poem then looks back. The "soothills of the alleghenies" once saw Victorians on "elegant excursions," and railroad logging that seems to compress "a hundred summers in a day." The poem seems to suggest that human busyness, even destructive busyness, is brief compared with the woods themselves.
The ending loosens into sound. Leaves, or perhaps the poem's own words, are "free to go / fluttering / muttering off / earthward," and the final lines, "warm / worm / words," shift by only a letter each time. The mood is quiet and gentle, and the speaker seems to accept decay as part of a cycle that feeds new life.