Rapid economic and demographic growth is changing the nature of Alberta s urban and rural landscapes. This has had profound effects on land use, particularly in areas near to Edmonton and Calgary where there is great concern about urban sprawl into surrounding farmlands. In 2012, town of Okotoks shifted from a finite growth policy to a continuous growth policy, thus eliminating a key policy constraint on urban development. This policy history makes Okotoks a natural experiment of land use policy. We selected Okotoks to reveal people s willingness to pay for open spaces, and most importantly, the causal effects of the municipal development policy on property values. Our study is based on a hedonic price approach with a spatial lag model as well as a spatial two-stage least squares. Under residential property transactions from 2010 to 2017 in Okotoks and surrounding area, we chose properties with developable lands in a 200-meter buffer as a treatment group, and those without developable lands as a control group, to incorporate Difference-in-Difference into the estimations. Results showed that people value pastures and forests within the 200-meter buffer, but disvalue the municipal policy of continuous growth. Individuals are willing to pay to avoid that policy. Acknowledgement : This research has been sponsored by the Alberta Land Institute and funded by the Max Bell Foundation, Calgary Regional Partnership, Alberta Land Institute, and Capital Region Board. Brookfield Real Property Solutions generously provided the housing transaction data used in this analysis.