Chasing Monarchs

"The monarch butterfly is our best-known and best-loved insect, and its annual migration over thousands of miles is an extraordinary natural phenomenon, though one that is poorly understood. Myths about the monarchs' travels abound, and to separate fact from fiction, Pyle set out late one summer to follow the wanderers south from their northernmost breeding grounds in British Columbia. He migrated with them down the Columbia, Snake, Bear, and Colorado Rivers, across the Bonneville Salt Flats, through Hell's Canyon and the Grand Canyon, to Mexico, then turned up the California coast to track…