In the region where rivers are trapped and cannot flow to the sea,

deposition fills a great basin.
erosion cuts deep V-shaped canyons.
erosion and weathering form natural stone bridges.
sediment is washed away.

The region described is the Great Basin, a large area of the western United States that covers parts of Nevada, Utah, California, Oregon, Idaho, and Wyoming. It is characterized by its lack of drainage to the sea, with rivers instead flowing into closed basins. The Great Basin is known for its deep V-shaped canyons, natural stone bridges, and sedimentary deposits.