The Columbia rolls blue and wide, sluicing through brown suede hillsides, glacier-flattened and sun-baked. Along the banks, apples ripen under a puffy-cloud sky. Jet skis whine; powerboats groan; fishermen wade into the shallows. I drive this road regularly, so the scene is familiar: torn-out orchards, newly planted vineyards, a fence to keep bighorns from dashing into traffic, painted rocks lauding various high school classes. On the horizon, mountain peaks sport dregs of snow. The day is gorgeous. It’s also hot as hell, over a hundred, and I’m racing to try to see some fish.

Which seems a little silly. We see salmon all the time, Kokanee usually, at home where the land-locked sockeye come to spawn each fall. Going to see salmon at a fish ladder is like going to see chipmunks at a zoo. But the newspaper reported last month that this has been a record season for sockeye, the largest since they began counting -- over 23,000 in one day -- and I realized I’d passed Rocky Reach Dam a thousand times and never stopped. So today is my day, I’ve decided, if I can beat the 4 p.m. closing time.

I take a hard left and stop beside an entry booth. U.S. Homeland Security. An armed guard asks for my picture ID and then waves me on, down a curved lane into another dimension. Parking lot lampposts hold pots of petunias in near-patriotic shades -- pink, white and blue. Signs direct visitors to a native plant garden, a visitor center, RV parking, and a large multicolored playground for kids.

Then you see the dam. None of the diversions compares with the shock of this arcing slab of concrete across the wide river. A large tube snakes around its edge like an industrial waterslide: a new juvenile fish bypass. Close to a mile long and up to nine feet in diameter, the bypass is designed to take young salmon and steelhead around the dam on their trip downriver. More or less the opposite of a fish ladder, it cost $107 million to build. The new bypass, though, is not the reason for the record run. Biologists say only that the run was "unexpected" and "hard to explain." In other words: A mystery.

The place is deserted, not one other car. It begins to dawn on me that a record run reported last month might not mean much this month. Undaunted, I park and head into the visitor center building, sleek-lined and dusty turquoise, a throwback to the 1960s, like something you’d see on I Dream of Jeannie. Another guard. A metal detector. Then I’m inside. I ask about fish, and the guard looks up from take-out Thai, glances at the clock, and points down the stairs to an empty room with three large viewing windows.

Nothing, nothing. Murky water. Sun glare on cement. Then it appears, muscled and purposeful. Not a sockeye -- a steelhead. Undulating like a belly dancer’s abs, all grace and power and seduction.

I hear my own voice echo off linoleum: A gasp, a cry, an exclamation.

Years ago I read an article where the author described watching young lovers in the Soviet Union walk arm-in-arm and marveled at how even in such a repressive setting -- surrounded by concrete architecture, straight-legged soldiers, Cold War tension -- tenderness endured. Then, the writer said, he began to notice joggers. Not just romance, but a more individual urge, too, thrived. The author was heartened, maybe even moved. Now I am, too.

Despite the oppression of roads and dams, concrete and steel, powerboats and pesticide run-off, a steelhead charges upstream. What magic. What mystery. It’s like young love -- like a mid-life marathon.

Another fish appears, and I cry out again. I can’t help it.

A digital ticker above the emergency exit lists the number of each species that passes through the dam. So far today the video monitor has counted 238 chinook, 242 steelhead, 28 sockeye, three lamprey. The miracle, I realize, is not just that the fish survive, but that they’re shepherded past this dangerous place. By biologists, engineers, activists, judges and ratepayers. We’ve made mistakes, God knows. No surprise there. The surprise is that, despite rancor and derision, despite terrorist protections and antiquated facilities, despite our ignorance, even, about why salmon runs swell or deplete, we can still, collectively, decide to spend $107 million to try to get juvenile fish downstream. Just so they can come back up. What hard-wired instinct is this? In a world of such weight and trouble, to care for a creature shorter than my shin.

Three minutes to closing. I decide to leave, only to find a motley group just arriving, people in business dress with name tags on. What brings them here, I cannot imagine. They look more chamber of commerce than eco-tourist. I pass them on the stairs. Then wait.

Within moments, I hear it: a cry of delight. Then another.

Ana Maria Spagna lives and writes in Stehekin, Washington.