In a series of treaties from 1871 to 1876, Canadian prairie aboriginal claims were extinguished and Indian First Nations were confined to reserves scattered throughout the prairies. In recent years, a number of First Nation claims have been brought forward based on unfair or illegal surrender or exchange of the original land. There are a number of possible economic losses stemming from such cases, but the largest source of economic loss likely stems from the loss of farmland and its associated loss of agricultural use. This paper reviews a procedure for estimating historical agricultural loss of use, discusses several key issues and presents an application based on a hypothetical case example.