REDDING, California.- A father and son are expected to face federal kidnapping charges after they tied up two U.S. Forest Service employees and held them at gunpoint inside a trailer in Northern California near Mount Shasta.

Forest Service Chief Tom Schultz said the two workers were conducting routine field operations in the Shasta-Trinity National Forest when they were detained Thursday. They were released early Friday morning after being held for more than 12 hours near Gunboot Lake.

“I want to express how deeply grateful and relieved we are that our two employees have been released safely. Their well-being remains our top priority,” Schultz said.

The 49-year-old suspect and his adult son walked around 2:30 a.m. Friday and left the trailer with an assault rifle and knives. He also told authorities he had grenades.

Shortly after Siskiyou County Sheriff’s Office deputies arrived in the remote area around noon Thursday, they deployed drones to help locate the trailer and began calling additional law enforcement agencies, including the FBI, for help.

FBI Sacramento Acting Special Agent in Charge Brian Tosh said it’s fortunate no one was hurt during the confrontation.

“Crisis situations like this don’t usually result in everyone leaving the scene safely,” Tosh said.

U.S. Attorney Eric Grant said he plans to charge both men with kidnapping federal employees, but no charges were listed in online court records Saturday afternoon.