CHEROKEE COUNTY, Oklahoma - A Michigan man is facing multiple rape and sodomy charges after authorities set up a sting to catch him meeting with an underage girl for sex, according to Cherokee County court documents.

Christopher Dale Adams, 27, of Lake Orion, Mich., reportedly made several trips to Oklahoma to meet the 13-year-old girl. He has been jailed on five counts of forcible sodomy and five counts of first-degree rape and is being held in lieu of $100,000 bond.

Court documents allege the girl's adoptive mother arranged for the sexual encounters.

Suspicion surrounded Adams' presence at Sequoyah State Park in early March, and rangers said they watched him as he spent time around the lodge area and also observed a sport utility vehicle driven by an older woman, according to an affidavit.

One of the rangers told another to watch the situation closely, court documents say.

Suspicions grew days later after Adams was stopped in an early-March traffic stop. At the time of the stop, a ranger said Adams' passenger was a 13-year-old girl. The ranger said he made a referral to the Oklahoma Department of Human Services after "being unable to establish any reason the two were together," according to an affidavit.

It was later determined that the child's adoptive mother dropped her off at the lodge to spend time with Adams, court documents say.

Rangers notified DHS and removed items for analysis by the Oklahoma Department of Investigation from the room where Adams was staying. In an interview with police, the girl reportedly said she and Adams had sexual intercourse on multiple occasions at the state park.

"[The rangers] did an outstanding job," Cherokee County District Attorney Investigator Mike Moore said. "I can't say enough about those two guys. That's old-fashioned police work right there."

The adoptive mother, Barbara Wynn, confessed to paying for Adams to travel to Oklahoma, and said she paid for the motel rooms on numerous occasions, an affidavit says. Moore obtained receipts he said show Adams and the girl had five separate extended stays, beginning last year, at northeastern Oklahoma motels and the state park.

A sting was set up on Thursday after the teen and her adoptive mother told authorities the time and place of the next meeting, and that Wynn already had reservations at the Days Inn in Wagoner, documents say.

When interviewed by Moore, the girl said she met Adams on Facebook.

"She seemed like they were in love, like it was a real relationship and [Adams] did, too," Moore said. "I interviewed him the day of the arrest and he confessed to me."

Investigators tell News On 6 that charges for Wynn also are expected. Moore said Wynn is about 70 years old and was a foster parent in Oklahoma for many years before adopting the girl.

When asked if he'd encountered a case like this before, Moore answered: "No. No. Not where the guardian is taking the child to the perp, no."