Abstract: Homesteading, not the ad coelum doctrine, is compatible with libertarianism. In the former case, one mixes his labor with unowned land and a means of establishing private property rights in it and what is owned is limited to just that which has undergone this process. In the latter case, homesteading a square mile of land enables the owner of it to extend his property rights in a pyramid shaped form from his holdings on the surface down into the core of the earth and up into the heavens, with no limit.