However, just above it, Lonnie’s guide Chris got slammed in the face by a wave that dislodged his contact lenses and rendered him temporarily blind. In that split second, Lonnie unintentionally paddled over the eddy fence and found himself spinning and smacking into the wall. I could hear his guides yelling from below, unable to help. It was impossible to paddle upriver. But Lonnie yelled back “I’m good!” as he bounced off the wall and braced hard, surfing the eddy fence for a moment. Then, luckily, the eddy spit him out the bottom, and he shot out upright, hooting and laughing.

“That was more fun than a tornado in a trailer park!” he said. “The most fun I’ve had since I went blind.”

I just shook my head.

Just before reaching camp, we pulled into a little side creek that drained out of Matkatamiba Canyon, one of the highlights of the entire journey. We pulled our kayaks up onto a small gravel beach and took a hike that entered a narrowing and twisting slot canyon. Soon the limestone walls were so close I could spread my arms and easily touch both sides. Lonnie and I scrambled together up the smooth, tight groove, which shrunk even more. In places, the bottom was barely a shoe’s width wide, and we had to climb above the tiny stream. To make it easier, I showed Lonnie a climbing technique called “stemming,” in which you spread both legs wide and press your feet against the rocks. The oppositional force keeps you from sliding down. Lonnie caught on to stemming quickly, and we moved upward, splaying our hands and feet.

Soon, we arrived at a massive amphitheater that flattened out into a natural rock patio. The entire place was a blind man’s dream, with curves, grooves, and striations to touch and acoustics that seemed perfectly suited to Tarzan yells. The walls were also excellent for bouldering, with distinct extruding holds, deep indentations, and tiny shelves. Rob and I showed Lonnie some bouldering techniques, and I climbed twenty feet up the sidewall, coaxing Lonnie upward behind me. As we ascended, I loudly slapped the good handholds and coached him how to place his toes in the pockets and to stand up, trusting his feet and balance. Getting back down was even more challenging, and I climbed below him, guiding his feet into the right positions. Lonnie said that, with his girls out of the house, he wanted to try all kinds of adventure sports, from ice climbing to tandem mountain biking, but especially rock climbing. I promised him that when we were back home, I’d have him out to Colorado to cut his teeth in the big mountains.

Back on the ground, I said, “I hope this is just the start of many adventures together,” and I squeezed his calloused hand.