BERGEN COUNTY - The owners of a horse missing from a Mahwah farm are becoming increasingly concerned.

"Chief" had gotten stuck in the mud Saturday, and when his rider got off to help him, he took off into the woods. He hasn't been seen since.

His 15-year-old owner, Mackenzie Vulgaris, is devastated. "Chief means everything to me," she says. "He's my best friend. I don't know what I would do without him."

The family is worried about Chief's safety and has been searching the mountains for him every day. "The number one concern is them getting out to the highway and either hurting themselves or somebody else," says Carl Bauer, of North Jersey Equestrian Center.

Bauer says Chief should be able to survive in the woods until he's found. "In an area like this, it could probably survive its whole lifetime," he says. "You have grass areas where it can eat, water that's very drinkable. That's really all it needs... a place to eat and drink."

The family saved the black and white horse from slaughter last year.  Since then, he and Mackenzie have been inseparable.

"I feel like he does love me back," she says. "I feel like he feels the same way as me."

Rescuers are searching by ground and by air to find the missing horse and bring him home.