Grey wolves from Oregon now appear to be thriving in California (where they disappeared from about 100 years ago).
Wolves have never been reintroduced to California, instead they were returned to Yellowstone, re-entered Oregan back in 1999, and then entered California in 2008.
Short of a sudden sustained assault on their numbers, they are back in California and are likely to multiply over the next few decades to take back up their position as apex predators. This should not be feared in any way, with sensible management, it could end up benefiting California, with healthier ecosystems, less car crashes caused by wildlife amongst many other benefits.