The Trustee cites authority for the proposition that instruments not entitled to be recorded do not impart notice to subsequent bona fide purchasers under the recording acts despite the fact that they may have been actually recorded in the real estate records. See, e.g., J.S. Graham v. First Nat'l Bank, 175 F. Supp. 81, 84 (D.N.D. 1959); Messersmith v. Smith, 60 N.W.2d 276, 280 (N.D. 1953); J.I. Case v. Sax Motor Co., 256 N.W. 219, 220 (1934) ("It is clear that if such mortgage was not receivable by the register of deeds because of failure to meet the statutory requirements, no constructive notice was given though the register of deeds received it and filed it."); Tenney Co. v. Thomas, 61 N.D. 202, 237 N.W. 710, 712 (1931) (noting that if the statutory prerequisites to recordation are not fully complied with, the mortgage cannot be properly filed or serve to afford constructive notice); Security State Bank v. Burnstad Farmers' Elevator Co., 60 N.D. 43, 232 N.W. 295, 296-97 (1930); Stoffel v. Sullivan, 49 N.D. 695, 193 N.W. 45, 46 (1923) ("The authorities are substantially unanimous that an instrument in the form of a . . . mortgage, but which, for some reason . . . is not entitled to be recorded, does not constitute constructive notice to subsequent purchasers or incumbrancers for value without actual knowledge. This rule has been announced many times by this court.");

It is true, as argued by counsel for plaintiff, that Section 35-0304, N.D.R.C., 1943, provides that one of the prerequisites for recording a mortgage of real property is that it contain "the post-office address of the mortgagee". The Supreme Court of this State has held that "if such mortgage was not receivable by the register of deeds because of failure to meet the statutory requirements, no constructive notice was given though the register of deeds received and filed it". Case Co. v. Sax Motor Co., 64 N.D. 757, 256 N.W. 219, 220; Messersmith v. Smith, N.D., 60 N.W.2d 276. The Trust Indenture states that party of the second part therein to be "The First National Bank of Dickinson, a National Banking Corporation, doing business at Dickinson, County of Stark, State of North Dakota". It is also true that such instrument does not, in so many words, state that the postoffice address of the party of the second part, is "Dickinson, County of Stark, State of North Dakota"; however, that is the clear purport of such words, and, in the Court's opinion, a contrary conclusion would be strained and unreasonable. This Court concludes that, as to such statutory requirement, the same was fulfilled.

Similarly, a landowner's mineral estate or interest in unextracted oil and gas, even when split away from the surface estate, is an interest in real estate and governed by the law of real estate mortgages. See, e.g., Messersmith v. Smith, 60 N.W.2d 276 (N.D. 1953). At the moment of extraction or severance from the subsurface estate, however, mineral interests immediately transform from realty into personalty and become subject to the requirements of Article 9. James J. White Robert S. Summers, Uniform Commercial Code § 22-25, at 1069 (3d ed. 1988). Accord Northern Trust Co. v. Buckeye Petroleum Co., Inc., 389 N.W.2d 616, 620 (N.D. 1986).

" Oil and gas leases are interests in real property in North Dakota. State v. Amerada Petroleum Corporation, 78 N.D. 247, 49 N.W.2d 14 (1951); Messersmith v. Smith, 60 N.W.2d 276 (N.D. 1953); Petroleum Exchange v. Poynter, 64 N.W.2d 718, 726 (N.D. 1954). Thus, interests in oil and gas leases may be subject to the rule against perpetuities in proper cases.