Interregional communication increases together with long-distance trade in precious materials, particularly in the Eastern Woodlands. Copper, mica, obsidian, and marine shell are widely traded, and objects made from them are status markers when they appear in burials. At Hopewell, on the North Fork of Paint Creek in Ohio, a great earthwork enclosure is built that surrounds a major earthen mound thirty feet high. The Hohokam peoples of the Sonora Desert in Arizona have ties to Mexico, as seen in ceramic objects of apparent ritual importance such as figurines. In the Arctic, marine hunting technologies are successful, and at Point Hope, Alaska, burial customs are elaborated with the significant carving of objects made from walrus ivory.