Just read an excellent post by someone in Minneapolis called Reetsyburger on her cleverly named blog You Are Where You Eat. The post includes all sorts of great information on grass fed, local, sustainable meat and why it totally rocks. Here's an excerpt (which quotes University of Wisconsin Extension):
From an environmental perspective, raising animals on pasture has many benefits. High quality, healthy pastures reduce soil erosion, improve water 
quality (a University of Wisconsin study showed that pastures are the “best” crop for reducing runoff and erosion), increase plant diversity, and provide high quality wildlife habitat... A variety of health benefits are associated with grass-fed meats. Grass-fed meat is leaner and lower in fat and calories than grain-fed beef... Additionally, studies have shown that grass-fed meat contains more of vitamins A and E, conjugated linoleic acids (CLA), and omega-3 fatty acids, all of which have been shown to lower cholesterol and high blood pressure, and decrease the risk of diabetes and cancer. There's loads more on the You Are Where You Eat blog itself, including a chart listing health and nutritional information of various kinds of meat, and a nice blurb about Thousand Hills Cattle Company. It's well worth a read.
