Research overview: the Wallis Annenberg Wildlife Crossing at Liberty Canyon

The Wallis Annenberg Wildlife Crossing, under construction over US Highway 101 at Liberty Canyon near Los Angeles, is among the largest wildlife crossings in the world and was conceived largely to rescue the genetically isolated Santa Monica Mountains puma population. This overview describes how years of GPS-telemetry and genetic research, including the saga of P-22, identified this precise location as the critical pinch point where a crossing could reconnect cats trapped south of the freeway with populations to the north. The overpass is designed to carry vegetation and funnel a range of wildlife across ten lanes of traffic. The overview frames the project as a landmark in road ecology, a case where movement science directly drove a major piece of conservation infrastructure intended to prevent local extinction.