The mountain lion was healthy, male, and young. He was born in the Santa Ana Mountains of southern California, probably in the dry, rugged hills near the seaside town of San Clemente. As a juvenile, he wandered through chaparral, hunting mule deer, jackrabbit, bobcat, and coyote. At 18 months, the lion— known as M6 to the scientist who tracked his movements— began to roam farther, looking for a home range of his own and a mate. One night M6 headed north. At midday he rested; when darkness fell, he resumed his trek. About 50 miles into his journey, he left the conifers of the higher peaks in the Cleveland National Forest and dropped down into the sage scrub of Coal Canyon. Its stony creek bed led him into a broad, sandy outwash. Here M6 took stock of his predicament. An eight-lane freeway, Highway 91, the major thoroughfare from Riverside County to Los Angeles, blocked his progress. Hundreds of cars every hour streamed past. M6 sniffed out a derelict underpass. It was noisy and uninviting, but he made it through, leaving the highway behind and entering the relative calm of Chino Hills State Park. For 187 days M6 stayed put, patrolling 12,000 acres of low, grassy hills. Then he started to move again. Chino Hills, apparently, wasn't big enough. Twenty-two times over the next 19 months, M6 made the journey back and forth under Highway 91. He became a street-smart lion, but the passage was always perilous. To reach the canyon, M6 had to work his way across two shrubless golf courses, which offered little in the way of protective cover, and past a stable. Before he could get to the freeway, he had to cross a double set of busy railroad tracks. This was, by any sentient being's measure, difficult terrain. Arc lights glared; traffic roared. Despite the obstacles, M6 stitched together an hourglass-shaped home territory of some 168 square miles between the Chino Hills and the Santa Ana Mountains. Coal Canyon connected the lobes of the hourglass. For M6 it had become a corridor of life and death. The lion could easily have been hit by a car (at least six mountain lions were killed by cars in southern California last year), kicked by a horse, or flattened by Amtrak. But M6 had little choice: The Chino Hills contained only enough prey to support one or two female lions. If M6 wanted to pass on his genes, he had to survive the Coal Canyon choke point. And life for this lion was about to get even harder. A developer had plans for 652 acres just south of the freeway: 1,500 houses, plus all the usual gas stations and fast-food outlets that attend the birth of a neighborhood. Building and paving would sever the already tenuous connection to Coal Canyon. According to Paul Beier, the scientist who collared M6 and tracked him for months, "the loss of this corridor would guarantee the extinction of the mountain lion from Chino Hills and endanger the entire population of lions in the Santa Anas."
A culvert underneath a heavily traveled freeway near Santa Ana, California, is being transformed into a safe and inviting passageway for mountain lions. The freedom to move from one wilderness preserve to another, in search of food or a mate, could ultimately ensure the local survival of the species.
