How authorities found missing Tenn. student Elizabeth Thomas and former teacher Tad Cummins

— -- The missing Tennessee teen who was allegedly kidnapped by her former teacher was found in an isolated cabin in northern California after authorities received a tip late Wednesday describing a possible sighting of the pair.

The Tennessee Bureau of Investigation received the tip around 11 p.m. Wednesday and the caller pointed authorities to a cabin in Cecilville, a rural area near the Oregon border with little to no cell service, TBI Public Information Officer Joshua Devine said.

The caller indicated that 15-year-old Elizabeth Thomas and her former teacher, 50-year-old Tad Cummins, may have been living in the cabin for a week-and-a-half, Devine said.

The Siskiyou County Sheriff's Office also received a similar tip from the same individual around the same time, the sheriff's office said.

Deputies in Siskiyou County located a 2015 silver Nissan Rougue at the cabin that matched the description of the car Cummins was driving, according to the sheriff's office. Investigators were then able to use the car's VIN number to confirm that it belonged to Cummins and kept the car under surveillance for several hours, Devine said.

Law enforcement then established a perimeter around the cabin and decided to wait until the morning to arrest Cummins as he exited the cabin, according to the sheriff's office. A citizen who had befriended the pair assisted police on the scene.

As daylight broke, Cummins was taken into custody, Devine said. Thomas family attorney Jason Whatley said a special police unit "swooped in" on the cabin with "force."

Elizabeth exited the cabin behind Cummins and was taken into FBI custody in Redding, California, authorities said.

Two loaded handguns were recovered in the cabin, as well as personal items belonging to the pair, according to the sheriff's office.

Cummins was transported to the Siskiyou County Jail in Yreka, according to the sheriff's office. He will be arraigned Friday morning.

It could take weeks to extradite Cummins, the FBI said.

Cummins faces charges in Siskiyou County for kidnapping and possession of stolen property, according to the sheriff's office. The charges are pending review by Siskiyou County District Attorney Kirk Andrus.

In Lawrence County, Tennessee, Cummins faces charges of aggravated kidnapping and sexual contact with a minor, said Attorney General Brent Cooper.

The U.S. State Attorney's Office for the Middle District of Tennessee also filed a federal charge of transportation of a minor across state lines with intent of having criminal sexual intercourse against Cummins, said U.S. attorney Jack Smith. The charge carries a mandatory minimum sentence of 10 years in prison.

Whatley speculated that Cummins had planned an escape to the Northwest, referencing the sighting of the two at a Walmart in Oklahoma City off Interstate 44, which leads to California.

There are "particular qualities in the Northwest that make it easy to disappear," Whatley said.

Elizabeth was described by authorities to be "healthy" and "unharmed," but they added that the main concern is the state of her emotional and mental well being. She will be flown back to Tennessee Friday morning on a TBI aircraft, Devine said.

The teen had been missing since she was allegedly kidnapped on March 13 by Cummins, who had been added to Tennessee's Top 10 Most Wanted list. A day after they disappeared, Cummins was fired from his teaching job at Culleoka Unit School, where Elizabeth had been a student in his forensics class.

Authorities credited citizens and the media for their involvement in helping to locate the teen. Investigators received more than 1,500 tips regarding the whereabouts of the pair, according to the FBI.

"It only takes one tip," Gwyn said. "This is yet another example of the value of the public helping us to rescue a kidnapping victim."

ABC News' Morgan Winsor and Emily Shapiro contributed to this report.