Income from the operation of a business on allotted land where the income is held to be derived from labor and the use of capital improvements rather than directly from the land itself has been determined to be taxable. For example, income derived from the operation of a motel or a smokeshop (Critzer v. United States, 596 F2d 708 (ct. Cl.), cert denied and Dillon v. United States 792 F2d 849 (9th Cir. 1986), cert. denied) have been held to be taxable.