Groundwater sapping, or simply sapping, is a slow process of erosion by which some canyons form. It is thought to take tens of thousands to millions of years; however, several classic examples of sapping are found to have been eroded by overland water transport. Examples of these include Box Canyon and Malad Gorge in south central Idaho, basalt canyons in Hawaii, canyons in the Atacama Desert and parts of the Colorado Plateau, including the Grand Canyon area. Overland flow can erode canyons rapidly, in harmony with the biblical timescale.