Subject to the rules of this chapter, a freehold estate, as well as an estate for years, may be created to commence at a future day; an estate for life may be created in a term of years, and a remainder limited thereon; a remainder of a freehold or an estate for years, either contingent or vested, may be created, expectant on the determination of a term of years; and a fee may be limited on a fee, upon a contingency, which if it should occur, must happen within the period prescribed herein. R.L.1910, § 6609.
Oklahoma Legal Code