My brother has been trying to kill me since before I got here.

He knew, before my mother and I drove out to Montana to visit him, that I was looking for new, mildly-to-moderately-frightening outdoor activities to try. Right away it was clear that we had a misunderstanding.

A few weeks prior to our trip, my brother sent me a text that read, “Skydiving?” I stared at it awhile before typing, “Are you serious?” If I could keep this column going for 65 more years, skydiving would be the very last activity I’d do in the very last week before I was expected to die. Even then, I wouldn’t do it. I would reschedule my skydiving appointment for three weeks later—“It’ll be fine,” I’d email my editor, “I’ve got a month left, easy.”—and then I would will myself to die before I could ever make it. [Ed. Note: Try me. I know your tricks, Heaney.] What do I have to prove? I’m 91 years old. Leave me in peace.

Almost all of my brother’s suggestions seemed to involve jumping off things, actually, to the point that I needed to clarify that I didn’t want to do anything in which I’d start at the top of something and end up, by the power of gravity, at the bottom. I need activities that allow for hesitance and escape. Whenever I’ve been about to take a little shot of bad-tasting liquid (be it cold medicine or cheap tequila), I’ve always needed a few minutes alone in front of the sink. I need time to come to terms with what I’m about to do. I need to be sure that I could pour whatever it is I’m holding down the drain, and nobody would have to know but me.

So I told my brother that I’d be going from bottom to top—that that was the only acceptable direction of movement. He offered up a climb of Mount Sentinel, and once I got to Missoula and saw the big concrete “M” built onto the side, seemingly not so far up, I agreed.

If the main problem with jumping from things is that there is no escape route part of the way through, the main problem with climbing them is that they’ll always look much shorter from the bottom. If I can see the top from here, how long could it possibly take to get up there? A minute? Two?

YOU CAN SEE THE “M”—for University of Montana, the letter having sat partway up Mount Sentinel, in various forms, since college kids put it there in 1908—from all over town. Our first day there, while I ride around town with my family, I keep an eye on it. The hillside it’s planted on is covered in scorched-looking yellow grass. It’s been an extremely dry fall. “Every day for, like, two months, it’s been sunny and warm,” my brother says. While we are there, it rains and rains, the wind piercing. At times, clouds cover the “M” completely, and at others they seem to cover everything but. It looks like an omen or a halo, depending.

On the morning we’re set to make the climb, I ask my brother if I should wear a jacket over my sweatshirt and he says no. “You’re worrying,” my brother says. “It’s not that cold, and it’s not that high, and I see people in terrible shape climb the M every day.” And he’s right: it’s not that high up, really. It’s a 620-foot climb. But those 620 feet take you from an elevation of 3,200 to 3,820 feet, and that ground is covered in just three-quarters of a mile.