Like many parks in central California, Pinnacles has had a small problem with wild pigs (a mix of feral domestic pigs and imported wild boars) disturbing the landscape on a regular basis. As of spring 2006, the core of the park was pig-free. The culmination of a twenty-year, $1.6 million effort had succeeded in eradicating pigs from the main area of the park. National Park Service personnel along with IWS worked to remove pigs from inside the park, and establish and monitor an exclusionary pig fence that runs for approximately around the center core of the park. Outside this fence, however, wild pigs still roam in regular abundance. Current monitoring for potential breaks and breaches in the fence is needed to ensure that the pigs do not return to devastate the park.