The winter wheat production system of the Pacific Northwest is characterized by severe wind and water erosion and winter annual grass weeds requiring high herbicide input. Since 1985, numerous multi- and interdisciplinary, long-term, large-scale, integrated cropping systems studies have been or are currently being conducted. The primary focus of these studies was on weed biology, ecology, and management, whereas secondary evaluations were on alternative cropping systems, conservation tillage, and fertilizer or herbicide inputs. The 6-yr integrated pest management project, conducted in the high-rainfall zone (> 400 mm), showed for the first time that when weeds were adequately managed, conservation production systems were more profitable than conventional systems. In the intermediate rainfall zone (350 to 400 mm), a recently concluded 6-yr, three-state study integrated single-component research results into a multifaceted approach to managing jointed goatgrass. This project has been used as a model study for other western states and the National Jointed Goatgrass Research Initiative. At present (9 yr thus far), a study is being conducted in the low-rainfall zone (< 350 mm) to examine the feasibility of no-till spring cropping systems in lieu of the highly erosive, weed infested, wheat–fallow system. Because of these projects, the Washington Wheat Commission recognized the importance of long-term, interdisciplinary, cropping systems research and has therefore established an Endowed Chair at Washington State University for direct seed cropping systems research. Federal, national, and regional agencies have used information from these projects for farm plans and pesticide usage.