Migration, along with growth and harvest, is one of three fundamental ways a natural resource stock can change. Migration across property lines makes the resource common property. This study models migration and the degree of common property along the continuum from the exclusive access of private property through limited access to open access. It was found that wildlife travelling under their own power are more likely to be common property than resources powered by exogenous forces such as the wind .. Pests have a higher degree of common property than valuable resources, faster growing resources a lower degree, and inexpensively managed resources a higher degree. Both exclusive access and open access are difficult to reach and most migratory resources will have limited access between the two extremes.