The specific objectives of this study are to: • Quantify the shift in animal agriculture toward more concentrated production on fewer, but larger livestock operations since 1982. • Quantify the extent to which livestock production has become more spatially concentrated. • Quantify the production of animal manure and manure nutrients, and describe trends. • Quantify the extent to which the production of manure nutrients may exceed the capacity of cropland and pastureland to assimilate nutrients. • Identify counties that are likely to have animal waste utilization and disposal problems (thereby updating the previous analysis by Lander, Moffitt, and Alt) and describe how the number of these counties has changed over time.