Ashby v. Hall
In Ashby v. Hall, 119 U.S. 526 (1886), the Supreme Court said (p. 529), speaking by Mr. Justice Field, "That the power vested in the legislature of the Territory (Montana) in the execution of the trust (under 2387), upon which the entry was made, was confined to regulations for the disposal of the lots and the proceeds of the sales. These regulations might extend to provisions for the ascertainment of the nature and extent of the occupancy of different claimants of lots, and the execution and delivery to those found to be occupants in good faith of some official recognition of title, in the nature of a conveyance. But they could not authorize any diminution of the rights of the occupants when the extent of their occupancy was established. The entry was in trust for them, and nothing more was necessary than an official recognition of the extent of their occupancy. Under the authority conferred by the townsite act the legislature could not change or close the streets, alleys and blocks of a town by a new survey. Whatever power it may have had over them did not come from the act, but, if it existed at all, from the general grant of legislative power under the organic act of the Territory."