Prosecutors say Clark took the girl by force to the back of an empty movie theater at a mall and attacked her.
Clark was arrested three weeks later.
Deputy District Attorney S. Kelly Cromer, who prosecuted the case, says Clark will not be eligible for parole until he's nearly 89 years old.
Jurors convicted Clark of forcible rape, kidnapping to commit another crime, aggravated sexual assault, sodomy of a person under 14, forcible lewd act on a child, and aggravated sexual assault and the special allegations of aggravated circumstances.
The Associated Press contributed to this report.