The Lord of The Rings and Lost star lives just streets away from the entrance of the park and saves up meat treats to feed to wild dogs.
And, despite warnings about his safety, animal-lover Monaghan insists he has no fear for his life.
He says, "I love that stuff. I got really close to a coyote and I've given him spare ribs... I brought some with me in my pocket.
"They're shy and they're not aggressive... They're like punk rock wolves. They're skinny and ornery."
And the star has no sympathy for owners of small dogs - like Jessica Simpson - who lose their pets to wild dogs.
He adds, "I love the fact that they're eating those little toy dogs. Less toy dogs, more coyotes. I don't like those little Paris Hilton yappy things."