"Unpatented mining claims", as used in section 3 (1)(b) of article X of the state constitution, includes mining claims located under the federal mining laws, 30 U.S.C. sec. 22 et seq., for which a patent has not been issued; and such term also includes leasehold interests in real property obtained under the federal "Mineral Lands Leasing Act of 1920", 30 U.S.C. sec. 181 et seq.
C.R.S. § 39-6-116