Frost has been quoted as saying the following:
Everything written is as good as it is dramatic. It need not declare itself in form, but it is drama or nothing.
"Stopping by Woods on a Snowy Evening" is a seemingly simple tribute to the beauty of nature, but Frost has made it dramatic by suggesting conflicting emotions in the speaker. He wants to stop "to watch his woods fill up with snow," yet he seems a bit worried about being seen doing this, especially by being seen by the owner of the woods whose "house is in the village." Why should he be concerned about being seen by the owner or anybody else? This question raised in the first stanza lends a dramatic feeling to the entire poem. What does the speaker have in mind? What does he want?
In the second stanza the speaker calls attention to his horse. This little animal is cold and probably hungry. It wants to finish this trip and get out of the dark, snowy night. Even the horse wonders why the speaker should be stopping here in the middle of nowhere on a snowy evening. Many critics have suggested that the speaker has a death wish--that he is thinking it would be easy to end all his problems by walking into those woods, so "lovely, dark and deep," and lie down in the snow. Freezing to death is supposed to be an easy way of dying. Frost, however, denied that there was any death wish in his poem. Evidently he was concerned with making it dramatic. Imagine the same poem without the owner, without the little horse shaking its harness bells, and without the words "The woods are lovely, dark and deep," which suggest that the mysterious trees seem to be pulling the speaker into them and offering him a pleasant death.
In the third stanza when the horse gives his harness bells a shake, the sound seems to pull the speaker out of his trance-like state. His horse reminds him that they should get going. Evidently the speaker has been to town on some errand and is on his way back home. If he were indeed thinking of committing suicide, he couldn't leave his patient, faithful little horse standing there in the falling snow. If the horse didn't freeze to death, it might go on to the nearest farmhouse, in which case the people there would be sure there had been a serious accident and would follow the road back to where the horse and sleigh had been standing.
In the last stanza the speaker is reminded that he has obligations and responsibilities. He has been far away in his solitary thoughts and now is returning to reality. Either he cannot just sit there looking at a beautiful scene, or else he cannot commit suicide on the spur of the moment. He has food for his family and probably Christmas presents in the sleigh. He regrets having to continue on his journey, but he has a long way to travel in his slow-moving horse-drawn vehicle before he gets home. The repetition of the line "And miles to go before I sleep" seems to suggest that he is also thinking that he has a long life ahead of him, with many problems to deal with, before he finally goes to sleep forever.
Even if the poem does not suggest a secret "death wish," as critics have claimed, it does seem to contain a thought about death. This is certainly understandable, and even appropriate, considering the time of year, the time of night, the darkness, the isolation, the coldness. Everybody thinks about death occasionally--but that doesn't necessarily mean that they want to expedite it.
Frost wrote "Stopping by Woods on a Snowy Evening" early in the 1920s, and he didn't die until 1963. He had a long life ahead of him after that snowy night when the glory of nature caused him to stop for a few minutes to watch a stand of trees being slowly covered by the drifting snow.