The flat paddy turned abruptly skyward as we approached the forest's edge. We were joined by several other women just as we began our climb, hand over foot along a washout gully punctuated by sharp limestone outcroppings. The summit seemed only a few hundred meters away but when I crested the hill it was only to see another, steeper one, and the retreating backs and flashing feet of the women disappearing into the undergrowth. The morning was already hot and windless, pregnant with humidity and clearly lacking in the oxygen necessary to sustain life. I struggled on.

The women were tireless, laughing and chatting as their stringy calves ate up the miles, their only concession to the heat the occasional banana frond they cut to fan themselves as they walked. It was with infinite relief that I heard chopping in the distance, the echoing puk-puk of wood on wood somewhere in the dense tropical forest. The path opened out into a clearing lined with meter-long sticks that had already been cut and split for kindling. My companions set down their baskets, pulled out sharpened machetes with homemade handles, and set to work.

Once the yearling trees were felled and hacked into the proper length, the women fashioned wooden wedges and mallets. They curled their bare toes around the base of each log and set to splitting it with tools that had existed before the age of bronze. They worked methodically; their calm, completely naive confidence in their own abilities made them seem somehow larger than life. I, who had been called a tomboy growing up, athletic and unfeminine, sat watching these tiny, graceful women swing a mallet with the strength and precision that it would take me years to match. It was a revelation.

But more was yet to come. When the wood was cut they fetched their baskets and began to fill them, carefully choosing each piece of kindling and placing it beside the others until every inch of space had been accounted for. They removed their head scarves, folded them into pads, squatted down to slide the bark forehead straps over their heads, then rolled smoothly onto their feet. One by one, like animals in a yoke, they passed me, plodding heavily under a load that exceeded their own body weight.

The climb down was now complicated by their heavy cargo, balanced only by the inclination of their necks. Their movements became a complicated and precisely choreographed ballet. They gathered at the tops of steeper sections and turned slowly to face the mountain before lowering themselves, stiff-backed, feeling for the handholds they dared not look down to see. Two young girls joined us on the lower slopes, one twelve years old and the other fourteen, each carrying a full load home to her family. Their apparent ease stiffened my resolve to try the yoke, but I was still coward enough to wait until the road had turned flat and smooth and we were a scant half mile outside of Mai Chau. The women paused to rest, and I traded my water bottle for a basketful of wood. I squatted, amidst great hilarity, to ease the strip of bark over my forehead. I rolled forward and struggled to shift the wood onto my back, and got no further than if I had been tethered to a fire hydrant. Several of the women, their baskets already in place, helped me to my feet. I stood, swaying dizzily, quite sure that someone had dropped a circus bear on my head, and that it was starting to dance. The load dragged my body backwards from a single point in the middle of my forehead. The effort to keep my neck stiff when I walked sent shock waves up and down my spine. I could almost feel my vertebra fusing with every step. I lasted barely two hundred meters before looking for a place to sit. When I collapsed the laughter redoubled. Everyone gathered around to pat my broad shoulders good-naturedly. The woman who took my basket back was barely five feet tall and lifted the hundred and ten pounds as though it was no heavier than a two-month-old child.

It hadn't always been this hard, they told me. A few years ago they had only to go to the edge of the forest to gather all the wood they needed. Lately the government had set up a three-mile buffer area around their village and allowed no logging within its limits. Despite my aching neck and fallen arches I applauded the new policy. Everywhere along the trail I had seen the hacked-off stumps of towering, first-growth trees. I knew the villagers depended on the forest for more than wood - they regularly gathered wild bananas and papayas, medicinal herbs, mushrooms and bamboo. If the trees suffered the same fate as the leopards then the White Thai way of life would end.

When I got home I dropped onto my mat and drifted into an exhausted sleep. It was a week before I could sit up without supporting my neck with one hand.