Excerpt from the report Summary: This report includes the results of a study of costs of owning and operating machinery on 3 sizes of spring wheat farms in central North Dakota in 1960. Most of the data were obtained by an enumerative survey of about 150 farms. Total costs are shown as costs per acre of use, including costs of implement, tractor, and driver. Total cost per acre for major tractor-drawn and self-propelled machinery averaged about 15 percent higher on farms in group I, those with 180 to 419 acres of cropland, than on farms in group III, those with 660 to 899 acres. Costs on farms in group II, those with 420 to 659 acres of cropland, averaged only slightly higher than on those in group III.