MIKE IS A WIT, peculiarly quick-minded. He has an ever-changing repertoire of voices, a dozen nicknames for me. We rarely get the chance to go into the mountains together anymore, so when we do, we gleefully revert to our younger selves.

At the base of the Diamond, Mike stacks the rope and, finally able to talk, says, "I suppose you think you're leading."

We both want to lead—it has been this way since the beginning—but, eager beaver that I am, I already have my rock shoes on. I point to them.

"I see, Rhubarb the Black's got 'iz scuppers on already," says Mike in his pirate's brogue. "Then the sharp end be yours."

Mike and I gravitated to each other as teenagers. We both lived on the edge of Laramie, the boundless prairie our backyard. We were predetermined to be wild and became perfectly matched partners in misadventure. Climbing came naturally to us, and

While learning how to climb, we made a pact: whining was prohibited. No matter how freaked you were, you had to keep your mouth shut.

we scaled everything in sight. University buildings, boulders, smokestacks, mountain walls—our adolescent enthusiasm and daring far exceeding our ability. Soon enough even wide-open Wyoming started feeling small. We lied about our ages, got jobs on the railroad, lived in a tent behind the Virginian Hotel in Medicine Bow, banked the cash, then left high school to spend half a year hitchhiking through Europe, Africa, and Russia, climbing and chasing girls. We got arrested in Tunisia, Luxembourg, and Leningrad. We got robbed. We slept in the dirt.

Through college at the University of Wyoming, Mike and I double-dated, debated Nietzsche, and stood back to back defending atheism, dismembering our Christian attackers with rapier tongues. We ice-climbed and skied the backcountry and went on expeditions. Close calls were commonplace, and we thought nothing of them. We pushed each other but willingly stood in for the other whenever one of us was weak or scared or lost. We were outdoor brothers-in-arms. We would die for each other without flinching—and almost did a dozen times.

"You're on," Mike announces, and I start up a dihedral between the wall and a delicate pillar. The pillar—ten feet wide, ten feet thick, and 200 feet tall—leans precariously against the Diamond. We have used this route to gain the upper face multiple times, but it always feels dicey. We console ourselves with the fact that the pillar has stood here for thousands of years.

Today the crack is running with water and dangerously slippery. Halfway up I mention this fact.

"Is that whining I hear?" cries Mike in his Monty Python voice. "Courtesy slack coming your way."

We were 16 and just learning how to climb and we made a pact that whining was prohibited. No matter how freaked you were, you had to keep your mouth shut. To enforce this rule Mike came up with a penalty called "courtesy slack": The belayer fed out extra rope—so you'd take a longer fall—whenever even a whimper was heard. Over the years, this bred a black, Brit-like humor in Mike. The more desperate the situation, the more he made fun of it: "It's absolutely grand—no handholds whatsoever" or "If the ice were only a wee bit thinner and more rotten I could actually enjoy myself." We were ripe with hubris. As far as we could tell we were indestructible.

At the top of the pillar I move onto the wall and set up a belay, and Mike begins climbing. I notice that he moves more slowly than he used to, but then he doesn't climb so much anymore. He has other passions now.

After college, we both did big expeditions—I went to Shishapangma and Everest; Mike walked the Continental Divide with his younger brother, Dan, then two years later mountain-biked it—but our priorities were diverging. The year I went to Everest, 1986, Mike took an internship in Washington, D.C., working for the hunger-relief organization Bread for the World. In 1987, we both went to Africa. With my girlfriend, Sue Ibarra, I climbed Mount Kilimanjaro and Mount Kenya and traveled far and wide writing adventure stories. Mike went to Swaziland to work for CARE, teaching poor Swazis how to get small-business loans. He helped start a daycare center. His girlfriend, Diana Kocornik, was teaching in Swaziland for the Mennonite Central Committee. Mike started going to church.

We all moved back to Wyoming in 1990, bought houses, and started families. When I got married, Mike was my best man. At his wedding, I was a groomsman—Dan was his best man. My daughter Addi and his son Justin were both born in January 1992; my daughter Teal and his twins, Carlie and Kevin, were born one month apart two years later. I kept writing stories; Mike took a job as the director of Wyoming Parent, a nonprofit family-advocate organization.

Halfway up the leaning pillar, he yells up to me, "Wish it were wetter in here!"