Crossing FAQ

Cougar Conservancy

Crossing FAQs


The wildlife crossing at Liberty Canyon will complete a wildlife corridor linking the Santa Monica Mountains to the Simi Hills range — with an overall goal to connect to the Los Padres National Forest — to restore habitat connectivity and prevent the imminent extinction of this subpopulation of cougars. Over the past several decades, this subpopulation has suffered from inbreeding and low genetic diversity, high rates of intraspecific killings, and vehicular casualties all related to the missing linkage. The National Park Service study has also recently discovered the first physical abnormalities linked to inbreeding depression when they captured a young male that has reproductive and tail defects, and they have documented, together with colleagues at UCLA, high levels of sperm abnormality in males. The biggest barrier to the movement of SMM cougars hemmed in by urban development and the Pacific Ocean is the 10-lane Highway 101, the proposed site of the wildlife crossing. Construction crews will break ground in early 2022 and it is estimated that the crossing will be complete by the end of 2024.

No, cougars and other wildlife are already living in the natural areas of the Santa Monicas and Simi Hills, including around the crossing on both sides of 101. The National Park Service estimates that only 10 to 15 adult and subadult cougars form a stable population within the Santa Monica Mountains – this is the area’s carrying capacity due to cougars’ territoriality, large home range requirements, and available habitat. The wildlife crossing will enable the introduction of much needed genetic diversity into the subpopulation by promoting movement among resident cougars.

Benson, J. F., J. A. Sikich, and S. P. D. Riley. 2016. Individual and population level resource selection patterns of mountain lions preying on mule deer along an urban-wildland gradient. PLoS ONE 11:1-16.