GREENFIELD — A California woman was found dead early Thursday morning after an apparent crash involving an all-terrain vehicle.

Bona Lisa Kim, 27, of Studio City, Calif., was found in a Cornwell Road field, unresponsive and not breathing around 1:30 a.m. on Thursday, said police Cpl. Glenn Roberge.

“We believe that it occurred sometime between 11:30 p.m. and possibly 1 a.m. because she was last seen alive at 11:30 p.m.,” he said.

She was taken to Monadnock Community Hospital in Peterborough where she was pronounced dead.

Roberge said police believe the ATV had flipped over while Kim was operating it.

Kim was staying at the horse farm at 243 Cornwell Road as a farm intern, he said. The horse farm family reported finding her.

New Hampshire Fish and Game are investigating the incident with police.

“The accident is under investigation, not suspected to be suspicious,” Roberge said.