Ah, winter. An invitation to an eccentric dance across glazed sidewalks into the arms of an orthopedic surgeon. A maelstrom of demented motorists swerving and fishtailing to avoid oncoming snowflake rounds. Sixteen ounces of slush in an eight-ounce shoe. Who needs this? Birds of a feather fly south or pass the dreary months curled up in their dens in front of warm and flickering VCRs.

Not Diana Kappel-Smith. She straps on a pair of snowshoes and hikes into the woods and meadows near her 275-acre Vermont farm, meeting winter on its own gelid terms. But what is there to see except the snow's blank face and the outlines of skeletal trees? Look closely, says Kappel-Smith; winter's world is a place of wonder: "In the winter everything out-of-doors seems to be gone. But . . . we know that nothing is gone, and that all the rich life of a June morning must be out there on a January morning."

Yet the signs and secrets of winter life, she says, are almost always small and written in code. Finding answers to winter's riddles (and learning to ask better questions) means being able to see clues in the commonplace. Every time Kappel-Smith returns from the winter woods, her pockets are stuffed with little treasures: a piece of maple bark "inscribed with the exquisite wriggling glyph of a bark-beetle larva"; a feather from an owl's breast. "What has it seen, this peel of owl? What winds, what distances, what blood?" Such fragments are runes for Kappel-Smith, oracles that whisper of the lives pulsing behind winter's deceptively bleak facade.

A groundhog hibernates beneath Kappel-Smith's lilac hedge, breathing once every six minutes, its body temperature throttled back to 36 degrees Fahrenheit until spring. But other creatures are awake and on the go. Kappel-Smith moves quietly and respectfully through the woods, seeing much that others miss. And whether she crosses paths with a tiny meadow vole, speckled salamander, bear or coyote ("I could see his thick fur moving in the wind like long summer grass"), the presence of all delights and fascinates her. She's an excellent writer, an accomplished artist (15 of her drawings illustrate the book) and a sensitive naturalist, so readers -- especially those who love the outdoors -- will share this delight.

But Kappel-Smith doesn't romanticize the harsh side of nature. Equally at ease examining unfolding maple buds or dissecting a bobcat's stomach, she recognizes that winter is "a requisite battle . . . a hard journey . . . and it pushes to the limit whatever inventive and seminal resources life has."

That includes her own life. "Wintering" is also a personal journey -- Kappel-Smith's observations on the "wintering of the human spirit," the hidden aspect of our being that "thrashes and resounds when it meets the world." Her writing on these matters is often cryptic, but understandably so. Describing the seasonal changes of one's soul presents a writer with more difficulties than peering into the darkness of the woods. Kappel-Smith handles both explorations with finesse and wry humor.

She is at her best, however, when describing winter's effects on animal and plant life. Everything interests her, and nothing escapes her attention. Whether she's examining a pinch of silvery fish scales ("all that a winter rain had left of a bit of otter dung on a rock by the river") or musing about the skills migrating birds must learn ("the syntax and vocabulary of darkness and light. Of magnetic dip and rise. Of stillness and motion"), Kappel-Smith achieves a synthesis of science and poetry.

She uses science as atool "because I have some experience and training in it, and I like it, and it's handy." But she's not a scientist, she explains, because she once made the mistake of doing research in a laboratory with a floor-to-ceiling window that overlooked a valley and wooded hills.

One day she suddenly looked up from her microscope and saw evergreens and mist rising and tree branches glistening with rain. "And something in me leaped and expanded so that the sensible casing which I held around myself cracked and fell to the floor." We may take the first steps in our investigations in a laboratory, Kappel-Smith says, but eventually we have to get outside.

Take "Wintering" when you go. It's a field guide for the spirit, a map to help us discover that "there are no paths . . . and there is a way between every stick and tree and stone and fence -- a world undressed, secretive, and filled."