GRAND CANYON

The team behind The Ever-Living Tree (1994) takes readers on a simulated five-hour pack-mule trip from rim to floor of the Grand Canyon—through millions of years of geological deposits- -and acquaints them with the ecology of the chasm carved by the Colorado River. Dawn breaks through the clouds of an early thunderstorm, summoning rim-dwelling coyotes out to hunt and eagles to soar above ``the peaks, valleys and trenches where ancient mountains once stood,'' a dizzying vista aptly caught in all its pastel splendor in panoramic spreads. The trail winds in pictorial close-ups past archaic rock paintings, bighorn sheep, Anasazi granaries now homes to squirrels, and other flora and fauna to the bottom, where trekkers can rest in a bunkhouse and mules can be corraled by the river. The return trip will take seven hours; Vieira makes plain that the canyon continues to change, day by day and over millions of years. Endpapers supply names and dates of rock layers; a timeline provides an additional frame of reference. A good general introduction to the subject. (chart, chronology, index) (Picture book. 5-8)