The Fifth Circuit has addressed whether Oklahoma drug convictions are categorically controlled substance offenses. The breadth of the Oklahoma schedules facially extends beyond those substances that are controlled under federal law. Specifically, the Oklahoma schedules contain at least two substances (Salvia Divinorum and Salvinorin A) that are not included in any federal schedule. The court declined to assess whether the Oklahoma statute is divisible, or whether the modified categorical approach applies. However, the court rejected the petitioner's argument because he provided no case law to show that Oklahoma actually prosecutes offenses involving Salvia Divinorum and Salvinorin A, and thus, had not established a realistic probability that the petitioner's conviction involved substances not included in the Controlled Substances Act.
The full text of Rodriguez Vazquez v. Sessions can be found here:
http://www.ca5.uscourts.gov/opinions/pub/16/16-60211-CV0.pdf