This study examines the effectiveness of growth management policies on influencing future patterns of exurban and suburban development. We initially estimate a spatially explicit model of residential development with parcel data in Sonoma County, California. This estimated model is then used to simulate the effect of urban growth boundaries (UGBs) versus allowing municipal sewer service expansion. The UGB policy decreases the amount of suburban development but is less effective in managing exurban development. The downzoning policy in agricultural and resource areas reduces the amount of exurban development, but only partially due to the prevalence of grandfathered lots in rural areas.