Mexican cession and " Kearney’s Code":
CONGRESSIONAL RECORD—Extensions of Remarks October 23, 2000  on a side note as concerns the Guadalupe-Hidalgo Treaty:
There was in fact a stipulation in effect under what is referred to as Kearney's Code, which stands still today that the Fed does not have enforcement authority over territory or other property the subject of which is under the then existing Treaty(ies) in pertinent part to wit:
I. Breaking Down the Principles of Ownership A. The law prior to Nevada Statehood.
1. The Mexican cession and "Kearney’s Code."
Nevada became a state on October 30, 1864. Prior to that time the area in question was part of the territory of Nevada. The territory of Nevada had been created out of the western portion of the territory of Utah. Utah Territory has been a portion of the Mexican cession resulting from the Mexican War of 1845–46. U.S. Brigadier General of the Army of the West, Stephen Watts Kearney, instituted an interim rule, commonly referred to as "Kearney’s Code," over the ceded area pending formal treaty arrangement between the U.S. and Mexico. The Mexican cession was formalized two years later with the Treaty of Guadalupe Hidalgo, February 2, 1848.
3. Only the states possess the authority to define property.
As a general proposition, the United States, as opposed to the several states, is not possessed of a residual authority enabling it to define property in the first instance.
The United States has performed the role of agent over lands which are lawfully owned by the union of states, or the United States. Individual States in the southwest, established laws deriving from local custom and court decisions (common law) for determining property rights. These were the local laws, customs, and decisions of the court affirmed by Congress in the Act of July 26, 1866. The Act extended this principle to all the western states and conferred a license on settlers to develop property rights in both the mineral estates and surface estate of the mineral lands of the United States.
4. The Act for Surveying Public Lands of June 4, 1897, also known as the Forest Reserve Organic Act which excluded all lands within Forest Reserves more valuable for agriculture and mining and guaranteed rights to access, the right to construct roads and improvements, the right to acquire water rights under state law, and continued state jurisdiction over all persons and property within forest reserves.
2. The courts insist that these laws must be read on pari materia (all together).
The courts have stated repeatedly that laws relating to the same subject (such as land disposal laws) must be read in pari materia (all together). In other words, FLPMA or any other land disposal act cannot be read as if it stands alone. It must be read together with all its parts and with every other prior land disposal act of Congress if the true intent of the act is to be known.
3. Each of these Acts contain "savings" clauses protecting existing right, including FLPMA.
All acts of Congress, relating to land disposal contain a savings clause protecting prior existing rights. FLPMA contains a savings clause protecting prior existing property rights. There is an obvious reason for this. Any land disposal law passed by Congress without a savings clause would amount to a "taking" of private property without compensation. This could trigger litigation against the United States and monetary liability on the part of the U.S.
The Presidential Executive Order which created the Humboldt National Forest contained a savings clause, protecting all existing rights and excluding all land more valuable for agriculture and mining. The Road was in existence long before there was a Humboldt National Forest. The Road was a prior existing right, having been confirmed by the Act of 1866 and related subsequent acts of Congress as well as court decisions. The Road was never a part of the Humboldt National Forest, and could not be made a part of the Humboldt National Forest without triggering the Fifth Amendment of the Constitution of the United States dealing with "takings" and "compensation."
Jarbidge Wilderness Area also contained a savings clause protecting prior existing rights.
B. The United States makes errant arguments claiming ownership of the Road.
1. The U.S. argument regarding "public lands" resulting from Mexican cession logically fails on its face.
The U.S. argues that the Mexican cession of 1846, ratified in the Treaty of Guadalupe Hidalgo in 1848, conveyed the Road and the land of the Road crosses to the United States, which some 150 years later remain "public land" unencumbered by private rights. If this argument is valid, the myriad other roads, highways, towns, cities, ranches, farms, mines and other private property which did not exist in the southwest in 1846 but which exists today also remain the sole property of the United States.
One cannot logically reach the first conclusion without accepting the later.
2. The true nature of "public lands."
"Public Lands" are "lands open to sale or other dispositions under general laws, lands to which no claim or rights of others have attached." The United States Supreme Court has stated: "It is well settled that all land to which any claim or rights of others has attached does not fall within the designation of public lands."  FLPMA defines "public lands" to mean "any land and interest in land owned by the United States within the several states and administered by the Secretary of the Interior through the Bureau of Land Management." The mineral estate of lands within the exterior boundaries of National Forests are administered by the Secretary of the Interior through the Bureau of Land Management.
As laid out in this report and in the hearing record, un-rebutted evidence presented in the Road dispute clearly demonstrates that the United States and its agent, the US Forest Service, have no claim to ownership of the Road. Control of property rights to the road clearly vests in the state of Nevada and Elko County on behalf of the public who created the road under the general right-of-way provisions of the Act of 1866. Even if Elko County disclaimed any interest in the road, the individual owners whose mines, ranches and other property are accessed by the road may have a compensable property right in the road.