Hiking Haleakala Crater- day one of epic adventure.

Trash out. Chickens and dogs fed. Backpacks, way too heavy, loaded into truck. Starbucks in hand (latte for me, Frappuchino for Mike.)

Now, I sit on the sidewalk babysitting the backpacks while Mike parks the truck at the exit point further down, and hitchhikes back up to the summit to the trailhead of the nastily-named Sliding Sands, where we begin. The air is thin, and cold, unfamiliarly bracing. I dig out the parka I haven't worn since the last time I was on the Mainland.

I'm apprehensive. As recently as yesterday I was in the chiropractor's office, getting the low back pain generated by our training hikes adjusted–but now, with the crisp sunshine, ten thousand foot elevation, caffeine buzz, and stubborn determination going, I can't wait to get going.

I've turned off my phone to save the battery and so I can take pictures with it, and I experience a wave of anxiety. We are about to launch ourselves, bad backs, titanium shoulders, and tricky hips, off the side of the volcano–and no one will be able to find us, or help us, or communicate with us. It's a weird feeling.

The nearby observatory buildings cluster like a hen and her round white eggs. A vast sweep of rusty, tiny cinders in shades of umber and burnt sienna seem to roll down into the crater like a frozen wave.

Mike gets back. We put on the packs. They are ridiculously heavy. We bicker a bit, Mike wanting to see if he can carry mine (worried about my back) but I'm giddy with thin air and nervousness and set off down the trail, and the decision is made.

We are going down a total of four miles on a deep-cinder-sand trail to the crater floor, then two more miles across the floor to a Park Service cabin called Kapala`oa Cabin. (the Whale's Tooth.)

We do okay until we reach the floor of the Crater and join tourists on horseback under a hospitable mamane bush for shade, and eat lunch, fending off (non-native) begging chikra grouse and yellowjackets.

Those last two miles, in deep sand, on the flat moonscape of the crater, assume a sort of distorted, nightmarish quality–surely, the cabin's just ahead. Only it isn't. Perhaps sitting, eating and resting wasn't a good idea.

There's a certain point in hiking where nothing much exists but your breath, the trail, the metronomic setting of one boot in front of the other. It's a little zen, only a whole lot less fun. But, we finally get there–and I discover that the greatest joy of hiking is taking off your boots at the end of a long hard day. Sublime.

It's quiet here, the kind of quiet that comes from wide open space, the bowl of sky touchable, nothing anywhere for utter empty miles but the hum of wind in the sparse grass and the far-off honking of flying nene geese.

The cabin itself is snug on the outside, rugged on the inside. Equipped with triple-height bunks made of naugahyde nailed over foam and a wood-burning stove, it's set up to sleep twelve Boy Scouts or menehunes.

Mike and I are happy to boil water that comes from a catchment tap and I go out into the open plain and lie on my back and watch the empty sky while he hikes away, planning tonight's photography projects. We both move very slowly.