A plane is built to travel in a straight line toward a destination, and a river, from the speaker's window, seems built to do the opposite. That contrast drives the poem. A passenger looks down at dusk, watches a river slip along beside the aircraft, and finds in it a lesson about ease. "Nothing relaxes like a river, / I learn up in the sky," the poem begins, and the word "learn" matters: the height gives a view the ground wouldn't. The river does "as you please," never hurried, never anxious, and the speaker, strapped into a seat with a schedule, is left to "ponder / graceful ease." By the end the lesson turns personal. The river vanishes, and the speaker is struck by a small failure of attention: "I never asked / your name."
The sound of the poem works like the river it describes. The opening quatrain is tidily rhymed: "river" with "sliver," "sky" with "nigh." Then the poem tips into playful chiming: "Wander, meander — / never pander." These words slide into one another, and "pander" is a sharp choice, since to pander is to flatter and please others. The river pleases only itself. A few lines later "ponder" picks up the same sound, so the speaker's thinking is literally an echo of the river's wandering. After that, the rhyme largely dissolves. Lines grow short and long without a pattern, and a line like "You fatten and thin" is itself thin and then wide in its vowels. The poem never forces a regular beat, so it has the loose, unhurried feel of something following a natural course. Even "Slant supply, and / then dogleg back" bends mid-sentence, the line break doing what a bend in the water does.
The imagery shifts with the fading light. At first the river is a "silver sliver," small and delicate. Later it becomes a "silver sword," a sharper and more dramatic image, as if the last light is catching it like a blade. Then comes "Your silver sword gets lost / as the light gets less," where the plain, almost childlike wording lets the darkness arrive quietly. The river's behaviour is described in friendly, nearly human terms. It is "playful in a sleek / and serious way," a phrase that holds two moods at once, and it "split[s] in two — / an island born between." Calling an island "born" turns a geographic feature into a small event with a life of its own. When the river reappears "lake-like, dappled with islands," the speaker admits, "I have to strain to see." The poem is honest about the limits of looking, and that prepares for the ending.
That ending is the most interesting move. All the way through, the speaker addresses the river as "you," the way one might talk to a fellow traveller in the next seat. The title does the same: it is "To a River," a poem of address. Only when the river is "gone" does the speaker notice what was missing from this one-sided companionship, which is a name. The tone shifts from admiration to a gentle, slightly rueful self-correction. Short lines, "Now you're gone. / I realize / I never asked / your name," slow the poem to a halt, like a final look back. The river could be named on any map, yet the speaker had treated it as a pleasing sight rather than something with its own identity. Because the poem is itself a kind of belated greeting, the missing name stings a little.
What makes the poem worth reading is how much it does with so little. It takes an ordinary experience, glancing out of an airplane window, and turns it into a small study of attention. It also plays with perspective: the speed and purpose of flight are quietly set against the river's patient wandering, and the river seems to win. The lightness of the language, with its rhymes and wordplay, keeps the poem from becoming heavy, while the final admission gives it a lasting afterthought. We often pass through beautiful things without learning who or what they are, and this poem catches that moment of realizing it just too late.