We stood on the shoulder of a concrete giant

In my ideal world, no river would suffer the interference of a dam. But give the Ohio its head, and commercial barge traffic would become a risky and intermittent affair. Coal fuels the economy here in south-central Indiana, and container barges carry tons of it daily. Like it or not, we depend on the fossil fuel and its regular riverine transport.

The John T. Myers Dam spans the Ohio just before it takes in the waters of the Wabash, a confluence viewable from a private cornfield. Charlie had found the point where the two rivers join forces some weeks ago, following maps and his nose. My birthday request was that he take me there. Because it was right on the way, we stopped at the dam and walked to a small visitors' platform. It was little more than a fenced-in slab of concrete overlooking one of the two locks allowing boat traffic to move past the structure upstream or down. A small fishing boat, dwarfed by the sheer walls of the lock - not to mention the massive steel and concrete construction of the dam itself - had just tethered to the hydraulic weir that moves up and down with the water level. The big doors on the upstream end of the lock groaned to a close, and the water level began to drop.

We sang out questions to the boat's occupants, wanting to know where they were headed, how the locks operated, whether just anyone with a line and pole could get the Army Corps of Engineers to go through the slow, powerful motions of opening and closing the doors to the river. This process, I later learned, involves the movement of 18 million gallons of water in about eight minutes. With far-off voices sinking lower by the minute, they answered as best they could: Yes, anyone could navigate the locks, a mere peanut like themselves or the 100-foot wide barge waiting its turn to glide into the longer adjacent lock.

The sudden arrival of a uniformed official in a golf cart gave me a start. What homeland security regulation could we possibly have breached, standing there in the tiny visitors' space? But the fellow smiled and asked if we'd like to come with him to the top to take in the view. He was on break - another lockmaster was opening the big upstream doors to the barge.

It was my birthday. It was as sunny and beautiful a summer day as anyone could order. Why not enjoy it from a perch above the Ohio?

I wondered then if Charlie had arranged this whole thing, but both he and our guide denied any such preplanning. We walked a pedestrian bridge across the first lock and watched as the barge eased through the now-open gates of the second with just inches to spare on each side. We peppered the fellow with questions that he answered with a wealth of information about the mechanics of the locks, river traffic, and the Ohio in its various moods.

Before heading topside, we stopped at the control room, where the second lockmaster was confirming that the barge was moored before lowering the water. He had a radio, computer monitors, and, of course, a clear view of the locks through the room's plate-glass windows. The one distraction, a hummingbird feeder surrounded by tiny diners, wings awhir, lent a touch of delightfully incongruous whimsy to the scene. We helped ourselves to water from a cooler and stepped into a small elevator.

From the catwalks at the dam's crest we could see down to the last graceful curve of the Wabash, and the broad blending of the two waters - our ultimate destination. To our left was Kentucky, to our right was Indiana, and straight ahead, Illinois. This was no place for anyone prone to vertigo - on a perch straddling three states, with fishing boats bobbing below like bathtub toys, and bank swallows swerving and dipping to and from nests tucked a few feet away under the structure's broad concrete lip.

I was not uncomfortable up there, but after a few heady minutes appreciating the view, I was quite happy to come back down to my rightful place ashore.

Soon we were walking between rows of newly planted corn toward the confluence of the Wabash and Ohio. The whorled leaves of the emerging seedlings formed cups, each holding a single jewellike drop of dew - diminutive dams against the coming drought of midday.

Standing at last on the point above the broadly merging waters, I gazed back at the behemoth cupping the river. For all its structural beauty, it looked forbidding and unnatural in the distance, inert and soulless. But now I knew better. I had seen the slow hydraulic pulse of its locks and the movement of boats and barges. Add a few friendly officials, a host of swallows, and (of all things) hummingbirds, and you've got a place with a life, even if you couldn't have guessed it from where we stood now.

Much as I wish I could have known the river before it was harnessed and parsed for navigation, I'm glad I had the chance to appreciate its grandeur from the big industrial shoulder of that dam.