While agriculture in the midwestern United States has often been associated with deleterious effects on stream ecology and geomorphology, identifying appropriate mitigation strategies requires an understanding of the values and ethical beliefs motivating such behavior. Fifty-five open-ended interviews with farmers in central Illinois reveal that environmental modifications such as agricultural drainage can be seen as a rational expression of local environmental valuation. Personal definitions of progressive or successful farming, aesthetic characteristics of the farm such as neatness and order, and ethical understandings of environmentally responsible behavior all drive farming decisions affecting the environment. Debate and dissent create a rich constellation of environmental values, which are constantly renegotiated. Illustrating the complex ways in which farmers perceive and interact with environmental systems allows for a better understanding of these important agents of change in agricultural environments.