A social studies unit and student workbook explore changes in land use that have occurred over time in a semiarid area of eastern Australia, the Back Lachlan District. Part of the "outback," the District consists of a huge level plain with low rainfall, only one river, and vegetation ranging from timber to grass and shrub. Chapter I elaborates on its physical characteristics. Chapter II explains that it was inhabitated by Aborigines from 30,000 years ago until the 19th century. They roamed in small nomadic groups, looking for edible plants and animals, camping near water. They had a Stone Age technology. Chapter III characterizes the white pioneer grazing stage from 1820-1866 as a period of increasing cattle grazing. Graziers moved cattle into the District from northern breeding areas to use it as a fattening area before the stock was driven south to market. Chapter IV relates a stage of deteriorating environmental conditions from 1866-1900 due to overgrazing. sheep raising replaced cattle grazing, expensive technological apparatus were required, operating costs increased, rabbits overran the land, and the human population decreased. Chapter V describes 20th century subdivision of the sheep-raising properties into smaller single-family farms. The government has introduced controlled stocking policies to prevent further environmental deterioration. The student workbook contains activities and questions to enhance student comprehension of each chapter. (AV)