A granite outcrop not far from our house rises steeply above the forest floor, providing expansive views of the surrounding countryside.

It is a wonderful perch to scramble atop, gaze off at the distance and contemplate one's place in the cosmos. We've taken to calling it Bald Mountain after a favorite small peak in Western Maine.

At first glance this vestige of the glacier that covered half of North America more than 15,000 years ago — the same Wisconsin Ice Sheet that carved out Long Island Sound, the Connecticut coastline and other more prominent features — appears impervious to geologic and meteorological forces.0 But a closer inspection reveals how nature is slowly but surely bringing Bald Mountain down.

The other day I absent-mindedly tugged at a slender birch sapling that had taken root in a narrow crevice, and a rock slab the size of a car windshield broke free, slid down a sheer face and smashed below into a dozen pieces.

The ground nearby was littered with countless other shards, suggesting the hill at one time had been considerably broader, taller and probably balder.

Over the millennia as forests gradually spread over bare rock, tree roots have exerted relentless, immense pressure in search of nutrients and water. Each season decomposing leaves have created more soil, and combined with the ravages of cold weather, the inexorable pulverizing has continued. An old-time stonemason once told me one way to split a rock is to drill holes in winter, fill them with water and let expanding ice do the trick.

Here in the East, where a moister, more temperate climate supports robust arboreal growth, the Appalachian Mountains have been steadily wearing down. When first formed about 480 million years ago they were nearly triple in height, as tall as the Rockies and the Alps.

Over in Asia, meanwhile, steadily upthrusting tectonics slowly add elevation to the world's tallest peaks.

We humans, whose life spans barely register as the blink of an eye, would characterize these as slow-motion processes, but by chronostratigraphic measures the dismantling of Bald Mountain has been taking place at warp speed. Even I, in a few short decades of casual observation, can detect degrees of deterioration.

The flat summit is marked by a golf cart-sized boulder called a glacial erratic, derived from the Latin word errare (to wander).

I like to tell friends that I spent weeks dragging this multi-ton rock up Bald Mountain, but in truth the monolith had been deposited there when the enormous glacier retreated. It rests a few yards from the edge of a steep drop-off and will tumble down when the hillside eventually collapses.

No matter. There always will be hills to ascend, and people will continue to climb them. Humans likely first sought out elevated places to hunt for prey; later they learned the military advantage of gaining the high ground; eventually they realized that rising to the top of even the smallest mound literally and figuratively is an uplifting experience.

The best explanation for scaling to the top, of course, was given nearly 100 years ago by British mountaineer George Mallory.

Asked why he wanted to climb Everest, he simply replied, "Because it's there."

As for me, I'm pretty sure Bald Mountain and the surrounding hills will be around for a while. Even though the hill is wearing down, climbing it continues to raise the spirits.