For instance, my own research shows at Southeastern and Southwestern Indians had property rights in land that encouraged agricultural productivity, and that California Indians had property rights to pinon forests that encouraged good stewardship. Similar research by law professor Bruce Johnsen of George Mason University shows that clan fishing rights to salmon streams in the Pacific Northwest led to selective harvesting that, in turn, allowed larger fish to pass upstream to spawn--a property rights system that explains why some streams in the Pacific Northwest have larger salmon to this day.