IN his previous book, the enduring bestseller "Blue Highways: A Journey Into America" (1982), William Least Heat-Moon strayed from the expressway to follow minor roads in the United States leading to places like Nameless, Tenn., and Dime Box, Texas. Along the way, he found that the squiggling meanders of the secondary roads that mapmakers mark in blue are more symbolic of the American character - and characters - than the straight and standardized four-lane "red" interstates. "Blue Highways" offered palpable assurance that the heart of the country was inventively, if not always virtuously, offbeat. There are echoes of "Blue Highways" in "PrairyErth," which draws its name from the old geologic term for the soils of the central grasslands. Standing in the monotonous and bleak terrain of the Flint Hills in Kansas, the last remaining large expanse of tall-grass prairie in the country, Heat-Moon ruminates on the emotional pull of the area. "I don't much understand why I am here," he muses, discerning almost instantly that whatever the reason it is not "to explore vacuousness at the heart of America." To get to the "Blue Highways," Heat-Moon started out from the middle of the country. "PrairyErth" begins there, too. Yet, by the previous book's standard of 13,000 miles and 38 states, Heat-Moon barely journeys at all. Instead, he resolutely surveys the biology, geography, and history of each quadrangle in the 744-square-mile portion of Kansas known as Chase County. What emerges is a series of deep-cored moments of time, with all the layered fecundity and intrigue of a geologist's freshly drilled sample. Better, perhaps, one should say that Heat-Moon shares with English poet William Blake the profound suspicion that one can fathom the world in a grain of sand. Under his intense delineation, the sparsely populated Great Plains county swells to the proportions of a sovereign territory, whose richness lies in the accumulated human and natural history deposited there. In synoptic retelling, "PrairyErth" sounds a little too calculated, like an old-timey Americana gift shop conveniently located in a rest area along the interstate. Indeed, a selected perusal of the quotations, anecdotes, lists, and interviews compiled by Heat-Moon will yield heartwarming nuggets. Few can resist stories like that told about Populist congressman "Sockless" Simpson of "Medcine" Lodge, Kan., who, when asked why he misspelled the name of his own town replied, "I wouldn't give a tinker's durn for a man who can't spell a word more than one way." But in Chase County, the quaint and the whimsical lie hard by a frequently tapped vein of irony. More typical of the stories that have become legend is the tale of the 19th-century farm wife who watches as the menfolk drain the well fighting a wildfire. Despite their efforts, the family's barn is destroyed. As the flames begin to lick the walls of her house, the farm wife grabs a churn and flings its contents at the advancing fire. There is just enough cream to save her home. In several important ways, "PrairyErth" is not about Chase County, Kan., but about reading, and the relationship between authors and readers. One senses a fair and effective honesty in Heat-Moon's report of the people he has met, the land he has trekked, and the local histories he has examined. Still, none would call this objective writing. It is a grand miscellany, fused into a work of literature by imaginative reconstruction. Heat-Moon calls this writing an act of participatory history. Clearly what makes the book's subjectivity so engaging is Heat-Moon's joyous orchestration of words and his corresponding faith that readers will want to hear them. How rare it is, in an era that has been dubbed illiterate, to find something like Mark Twain's exuberant and respectful compact with readers. Always aware of the audience, Heat-Moon sometimes pauses to tease, withholding the punch line of a story until the paragraphs on local history have been duly studied. He is at his best when he lets his words chime with prairie sound. He recreates the itchy whack of wind-thumped grasses, and molds a picture-poem of a "yipping, ululating, singing, freely, freely, night-flute coyote." In American fiction, the prairie has often served as a testing ground. Willa Cather, in "My Antonia," saw its vastness as absently capable of blotting out the individual. But Heat-Moon views the prairie through the old-fashioned concept of a habitation, a place lived in by individuals. It is that, but not simply that. At the end of the book, Heat-Moon's understanding of the prairie is encoded in a parable. After hiking the trail that the Kaw, the native American people of the region, tread into exile in Indian Territory, Heat-Moon and his traveling companion experience the implied presence of their ancestors. "What brought them in?" the companion asks. "Memory," responds Heat-Moon. "Ours or theirs?" the companion inquires. "Yes," replies Heat-Moon. That is the short version. The full text is "PrairyErth," whose more t han 600 pages show that the land and its history are interwoven physical and psychic spaces, powerfully recoverable through human imagination and resourcefulness.