Los Angeles County has approved a 1,300-acre development near Castaic Lake in a region where mountain lions already struggle to move through roads, sprawl, and shrinking habitat.

The Center for Biological Diversity sued the county over the Northlake project, warning that it would pave over a stream and block a critical wildlife path for mountain lions and other animals.

The Signal described the project as a major development on more than 1,300 acres near Castaic, with renewed legal challenges over environmental concerns.

This fight comes at a critical time for California’s big cats.

Southern California Mountain Lions Need Room To Move

In February 2026, the California Department of Fish and Wildlife announced that state officials found threatened-species protections warranted for mountain lion populations in parts of Southern California and the Central Coast.

These cats are not declining because of one threat. They are boxed in by many.

CalMatters described mountain lions trapped by development, killed by vehicles, harmed by rat poison, and threatened by inbreeding. Citizens for Los Angeles Wildlife says local populations in the Santa Monica and San Gabriel mountains face habitat loss, vehicle strikes, rodenticides, and genetic isolation.

Connectivity Is Not Optional

Southern California has already recognized the need to reconnect habitat. The Guardian reported that the Wallis Annenberg Wildlife Crossing over the 101 freeway is nearing completion and is designed to help mountain lions, bobcats, lizards, and other animals move through a fractured landscape.

Northlake raises the same question in another place: will land-use decisions protect wildlife movement, or close another door?

Los Angeles County should rescind the project approval, require a new environmental review, protect the creek corridor, account for western spadefoot habitat, and preserve movement between wildlands.

Mountain lions cannot survive on isolated islands of habitat. They need connected land where they can hunt, breed, disperse, and maintain genetic health.

Sign the petition to urge Los Angeles County to stop the Northlake development from blocking mountain lion habitat connectivity.