DBS..I'm an admitted dumbass about this so I had to look it up. According to what I read, there are not too many areas effected by Enclave status.
In United States law, a "federal enclave" is a parcel of federal property within a state that is under the "Special Maritime and Territorial Jurisdiction of the United States."[1] As of 1960, the latest comprehensive inquiry,[2] only seven percent of federal property had enclave status, of which four percent (almost all in Alaska and Hawaii) was under "concurrent" state jurisdiction. The remaining three percent, on which some State laws do not apply, is scattered almost at random throughout the United States. In 1960, there were about 5,000 enclaves, with about one million people living on them.[3] These numbers would undoubtedly be lower today because many of these areas were military bases that have been closed and transferred out of federal ownership.
Under Evans, Congress has the power, if it chooses, to authorize the enforcement of all state laws on federal enclaves. It need not "retrocede" or "relinquish" federal jurisdiction. Instead, it can—to use Offutt Housing's language—simply "permit" all state laws to apply to all federal property regardless of "federal enclave" status.[46]
Also...For many years, it was believed that "the vast majority" of National Forests were not federal enclaves.[70] However, federal appeals courts in North Carolina, Michigan, and Oklahoma have recently ruled that "cession" statutes in each of those states ceded concurrent jurisdiction over National Forest lands acquired by the United States before February 1, 1940.[71] Depending on the wording of "cession" statutes in other states, these cases may mean that the United States has considerable concurrent "enclave" jurisdiction in National Forests.[72]
But it still remains beyond my comprehension how the Feds can "own" all that land ( 84% in Nevada ) within a State border ?
http://constitution.laws.com/article-4/federal-property