Okla. Stat. tit. 21, § 1624

The total or partial erasure or obliteration of any instrument or writing, with intent to defraud, by which any pecuniary obligation, or any right, interest or claim to property is or is intended to be created, increased, discharged, diminished or in any manner affected, is forgery, a Class B3 felony offense, in the same degree as the false alteration of any part of such instrument or writing.