USDA released March 2010 a Commodity report for Oregon. The report gives a detailed summary for the last 5 years for the State. This link will direct you to view the Wheat Commodity Report for Oregon. This report is more specific by County for the State of Oregon. The report lists detailed information by County for Wheat yields, Acres, Revenue.
This link will direct you the Extension Service Oregon Agriculture Information Network (OAIN). From the link you will see that you can find an abundant of information on other commodities. Also you will see there is a commodity report for grass seed. The site also has other useful links.