Mountain Lion Safely Released Back Into Wild After San Francisco Detour

The 2-year-old lion dubbed "157M" was found to be in excellent health after being tranquilized and transported from between two Pacific Heights apartment buildings.

Jan. 28, 2026 at 3:23pm by Ben Kaplan

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A 2-year-old mountain lion that had wandered into San Francisco's Pacific Heights neighborhood was safely released back into the wild in the Santa Cruz Mountains on Wednesday. The lion, known as 157M, was tranquilized on Tuesday and transported to his natural habitat after biologists determined he was in great health despite his accidental urban adventure.

Why it matters

Mountain lion sightings in San Francisco are rare but can cause concern among residents. This incident highlights the work of wildlife officials to safely return wild animals to their natural habitats when they inadvertently venture into urban areas.

The details

After being contained in a tight space between two apartment buildings, 157M was tranquilized around 10:30 a.m. on Tuesday. He didn't fully wake up until between 2 and 3 a.m. on Wednesday, at which point a biologist opened the cage and 157M bounded forward into the Santa Cruz Mountains forest.

  • 157M was tranquilized around 10:30 a.m. on Tuesday, January 27, 2026.
  • 157M fully woke up between 2 and 3 a.m. on Wednesday, January 28, 2026.
  • 157M was released back into the wild in the Santa Cruz Mountains on Wednesday, January 28, 2026.

The players

157M

A 2-year-old mountain lion that had wandered into San Francisco's Pacific Heights neighborhood before being safely captured and released back into the wild.

Krysten Kellum

A public information officer for the California Department of Fish and Wildlife.

Santa Cruz Puma Project

A research group that had previously placed a collar on 157M as a kitten to track his movement and behavior.

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What they’re saying

“It's a happy ending for this guy.”

— Krysten Kellum, Public Information Officer, California Department of Fish and Wildlife (sfchronicle.com)

What’s next

Residents and researchers will be able to track 157M's movements on the Santa Cruz Puma Project website within the next two months now that he has been outfitted with a new tracking collar.

The takeaway

This incident demonstrates the careful work wildlife officials undertake to safely return wild animals to their natural habitats, even in urban areas like San Francisco where mountain lion sightings are uncommon but can raise concerns among residents.