“Yes, yes, yes,” Brennon said. “This is what I do for a living. I make them and I test them. Do I have to give you a sworn affidavit to be believed?”

“Okay,” Phillips said.

“At least make them wait a few hours,” I said.

“Why?” Brennon asked. “So we can risk a downpour?” He turned to his men. “Let’s get going.”

I walked downstream. When I glanced back, Phillips’s eyes were still on the river.

I sat down beside Allen and we watched as four of Brennon’s crew shouldered the rolled-up polyurethane and waded into the water. When they got midstream they fastened it to the metal and began to work their way back toward shore. The dam unfolded like a huge flag. The river surged against the taut polyurethane, but the first section held. The dam was an A-frame, something I hadn’t realized until I saw the middle section unfold.

As Brennon’s crew installed the second section, one of the workers slipped. One moment he stood by a metal brace, and the next he hurtled downstream toward Wolf Cliff Falls, his arms flailing for a hold that wasn’t there. Suddenly his rope jerked tight. The worker was dragged and jolted across the current toward shore, the man holding the rope now joined by two other men in a tug-of-war with the river. They didn’t quit pulling until he lay on a sandbar gasping for breath. He refused to go back in.

Joel had made his way upstream and stood directly across from Randy and Ronny. When he got their attention he shook his head.

“Is he telling them not to go in?” Allen asked.

“Yes, that it’s too dangerous.”

Brennon’s crew worked in shallower water now and their progress quickened. The crowd on the shore became more attentive. Several of the men shouted encouragement. A woman lifted a crying child so it could see better. The teenagers quit splashing each other and watched the men struggle to anchor the last of the polyurethane.

The Kowalskys had been standing away from everyone else. But now they came to the pool’s edge. Wearing hiking boots, jeans, and a flannel shirt, Herb Kowalsky had dressed appropriately for the descent into the gorge, but his wife had not. Ellen Kowalsky’s sole concession to the terrain was a pair of black Reebok walking shoes, but the incongruity of her mismatched outfit did not lessen her dignity.

She had evidently slipped during the descent, for mud stained her right leg and the side of her dress. She stood with her feet slightly apart, one hand clasping her husband’s upper arm as if she too bolstered the final link of the dam.

Water hammered against all three sections of polyurethane. The dam bowed against the pressure as the water rose, but it held.

“It’s going to work,” Allen said, as I raised my Nikon and took several shots of the completed dam.