Calling a river "senile" is a rude way to begin, and the rudeness is the point. Rivers are usually granted a solemn permanence, yet Al Fowler's speaker addresses this one like a muddled old man who has forgotten what he was doing. The argument comes in two moves. First there is a catalogue of everything the river has piled up over unimaginable time. Then comes a verdict that all of it weighs less than the quiet of a child absorbed in wonder. Age and size, the poem insists, are not the same thing as worth.
The first half works by shrinking the grand into the domestic. The riverbed becomes a "floor littered / with aeons of pointless garbage," as if deep time were a messy room nobody has tidied. "Aeons" is a word built for awe, and "garbage" drags it straight down. What the river has collected are "slender frameworks of beast," a phrase that drops its article and comes out as bare and clipped as the bones it describes. Since the Mesozoic is named a few lines later, it is tempting to picture dinosaur skeletons, though the poem never says so. Beside them lie "granite leftovers from / a mountain eaten during the mesozoic." Here the poem commits to one metaphor, erosion as appetite. The river held a "lusty banquet" in its "middle age," and what remains are table scraps. The line break after "from" leaves the word hanging, so the mountain arrives slightly late. The soft m-sounds of "mountain," "mesozoic" and "middle" roll through the passage like heavy water.
Then the tone shifts. "let it be said" sounds like a formal ruling, almost an epitaph. The sentence delays its blow by breaking after "the," so the stressed word "Least" lands at the start of the next line, capitalised where the poem's habit is lowercase. The river is "less than the / Least silence / of any entranced youngster." Hushed s-sounds run through "less," "Least," "silence," "entranced" and "youngster," so the line quietens as it goes. Measuring a river against a silence is a clever choice, because a silence has no mass at all. An entranced child is doing nothing, yet is wholly attending, and the poem treats that attention as heavier than a mountain's worth of rock.
The last two lines complete the reversal by borrowing the river's own appetite. The river feasted, and the child "gulps," but what is swallowed is "a nascent universe," not the wreckage of a mountain. "Nascent" is the exact opposite of "senile." The capital on "Who" is another small oddity, as though the child's clause has been quietly promoted. "Unlikely breath" is the most striking phrase in the poem. It suggests that each breath is improbable, a small miracle of chance. Judging by the imagery, it is also the one thing the beasts on the riverbed have lost. Their skeletons are what is left when breath stops, and the child is breath continuing.
Formally, the poem is free verse, with no rhyme, no steady metre and lines that swing from the short "senile river," to the long "with aeons of pointless garbage." Punctuation is sparse. "Garbage" runs into "slender frameworks" with no comma between them, so the items settle together like sediment. That looseness suits a poem about erosion and accumulation. It also makes the final word, "breath," feel all the more human after so much geology.
What makes the poem worth reading is its willingness to flip an expected hierarchy. We are trained to feel small before deep time, and Fowler's speaker refuses. You could call that unfair to the river, which can hardly be blamed for being old. But the verdict is the speaker's, not nature's, and the unfairness gives the poem its energy. In this picture the mountains, bones and aeons are all finished. The one thing still alive to the universe is a child, quietly taking it in.