In class today i wanted to bring this up in class but didn't get to, i am not completely sure about this but i wanted to put the idea out there. Frost says "The leaves are all dead on the ground" which shows what time of year it is fall or the very beginning of winter. then he goes on to say "Save those that the oak is keeping" which shows that he wants to keep the leaves and the feeling of life or summer alive as long as he can. then he says "To ravel them one by one, And let them go scraping and creeping" and i looked up the meaning of ravel and it means a tangle or cluster, and the scraping and creeping part could be him raking the leaves because when you rake leaves you ravel the or put them into a cluster and the rake itself could sometimes make scraping and creeping noise. Then the poem says " Out over the crusted snow, When others are sleeping" which going with the raking leaves idea could mean whoever the person is in the poem is outside raking leaves at night while everyone is sleeping trying to clear the leaves that are on the thin layer of snow. This is my idea, comment on my thing and let me know what you think.
"The leaves are all dead on the ground,
Save those that the oak is keeping
To ravel them one by one
And let them go scraping and creeping
Out over the crusted snow,
When others are sleeping."
http://www.poetryfoundation.org/poem/238118