43 C.F.R. § 3864.1-1

(a) Land entered as a millsite must be shown to be nonmineral. Millsites are simply auxiliary to the working of mineral claims. R.S. 2337 (30 U.S.C. 42) provides for the patenting of millsites.

(b) To avail themselves of this provision of law, parties holding the possessory right to a vein or lode claim, and to a piece of nonmineral land not contiguous thereto for mining or milling purposes, not exceeding the quantity allowed for such purpose by R.S. 2337, or prior laws, under which the land was appropriated, the proprietors of such vein or lode may file in the proper office their application for a patent, which application, together with the plat and field notes, may include, embrace, and describe, in addition to the vein or lode claim, such noncontiguous millsite, and after due proceedings as to notice, etc., a patent will be issued conveying the same as one claim. The owner of a patented lode may, by an independent application, secure a millsite, if good faith is manifest in its use or occupation in connection with the lode and no adverse claim exists.

(c) The Act of March 18, 1960 (74 Stat. 7; 43 U.S.C. 42(b)), amends R.S. 2337 to allow the holders of possessory right in a placer claim to hold nonmineral land for mining, milling, processing beneficiation, or other operations in connection with the placer claim. Applications for patent for such millsites are subject to the same requirements as to survey and notice as one applicable to placer mining claims. No one millsite may exceed five acres and payment will be $2.50 per acre or fraction thereof.