43 U.S. Code § 935 - Several roads through canyons
Any railroad company whose right of way, or whose track or roadbed upon such right of way, passes through any canyon, pass, or defile, shall not prevent any other railroad company from the use and occupancy of the said canyon, pass, or defile, for the purposes of its road, in common with the road first located, on the crossing of other railroads at grade. And the location of such right of way through any canyon, pass, or defile shall not cause the disuse of any wagon or other public highway located therein on March 3, 1875, nor prevent the location through the same of any such wagon road or highway where such road or highway may be necessary for the public accommodation; and where any change in the location of such wagon road is necessary to permit the passage of such railroad through any canyon, pass, or defile, said railroad company shall before entering upon the ground occupied by such wagon road, cause the same to be reconstructed at its own expense in the most favorable location, and in as perfect a manner as the original road: Provided, That such expenses shall be equitably divided between any number of railroad companies occupying and using the same canyon, pass, or defile.
Section repealed by Pub. L. 94–579, title VII, § 706(a), Oct. 21, 1976, 90 Stat. 2793, effective on and after Oct. 21, 1976, insofar as applicable to the issuance of rights-of-way over, upon, under, and through the public lands and lands in the National Forest System.