Briggs, Rebecca S., 1973-2009-05-082009-05-082009-03https://hdl.handle.net/1794/9129xii, 84 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.Developed in 1973, Oregon's agricultural lands preservation policy sought to stop the conversion of agricultural land to other uses, particularly in the Willamette Valley. This thesis analyzes the effectiveness of this policy in preserving agricultural land in large blocks in the Willamette Valley, examining trends at the county, regional, and state levels. State land use data are used to assess whether the 1989 and 1993 efforts to strengthen the original legislation slowed the rate of agricultural land use conversion.en-USThesis