Federal Enclaves definition: A federal enclave is land over which the federal government exercises legislative jurisdiction. ( Kelly v. Lockheed Martin Services Group (D.P.R. 1998) 25 F. Supp.2d 1, 3.) The federal power over such enclaves emanates from article I, section 8, clause 17 of the United States Constitution, which gives Congress the power "To exercise exclusive legislation in all cases whatsoever" over the District of Columbia and "to exercise like authority over all places purchased by the consent of the legislature of the state in which the same shall be, for the erection of forts, magazines, arsenals, dockyards and other needful buildings." An enclave is created when the federal government purchases land within a state with the state's consent, which may be conditioned on the retention of state jurisdiction consistent with the federal use. ( Paul v. United States (1963) 371 U.S. 245, 264-265 [83 S. Ct. 426, 437-438, 9 L. Ed. 2d 292, 304-305].) Unlike those situations where the United States has a mere proprietary interest in a piece of land, the voluntary cession of land by a state to the federal government is an actual transfer of sovereignty. (Vincent v. General Dynamics Corp. (N.D.Tex. 1977) 427 F. Supp. 786, 795; see also People v. Crusilla (1999) 77 Cal. App. 4th 141, 148-150 [91 Cal. Rptr. 2d 415].) When an area becomes a federal enclave, Congress assumes the power of legislation over that area. Federal law thus applies, although not "every vestige of the laws of the former sovereignty must vanish." ( James Stewart & Co. v. Sadrakula (1940) 309 U.S. 94, 99 [60 S. Ct. 431, 433-434, 84 L. Ed. 596, 600, 127 A.L.R. 821].) State law which is in effect at the time of the cession, and which is not inconsistent with federal law, will continue to apply within the enclave unless it is abrogated by Congress. (James Stewart & Co. v. Sadrakula, supra, 309 U.S. at p. 99 [60 S. Ct. at pp. 433-434, 84 L. Ed. at p. 600]; see also Pacific Coast Dairy v. Dep't. (1943) 318 U.S. 285, 294-296 [63 S. Ct. 628, 630-631, 87 L. Ed. 761, 766-767]; Celli v. Shoell (10th Cir. 1994) 40 F.3d 324, 328, fn. 4; Snow v. Bechtel Const. Inc., supra, 647 F. Supp. at p. 1521.) State law which did not exist at the time of cession will also extend to the enclave when the state regulation has been expressly permitted by Congress. ( Goodyear Atomic Corp. v. Miller (1988) 486 U.S. 174, 180 & fn. 1 [108 S. Ct. 1704, 1709, 100 L. Ed. 2d 158, 168].)