The man, Daniel Dean Divine, 30, is being held in Oregon, awaiting extradition proceedings, The Salt Lake Tribune reported.
Duchesne County sheriff's deputies said in an arrest warrant for Divine that he sent the girl an iPhone. It was already loaded with pictures of a shirtless Divine holding a teddy bear the girl had given him.
The 13-year-old asked her mother for help because she could not figure out how to take pictures with the phone, deputies said. Her mother, 35, then asked her daughter if she was sure about sending the pictures and then helped her.
The mother, whose identity was not reported to protect her daughter's identity, called Divine a "very good friend of the family" and said he and her daughter planned to wait to have sex until after the girl turned 18. Both Divine and the mother are charged with sexual exploitation of a child, and Divine also faces a misdemeanor count of enticing a child through the Internet.