The Amu River runs through the Great Desert on Dinotopia's eastern side. It begins to the north in the Backbone Mountains and ends at the Portal. Canyon City and Pteros are found along the river as are the ancient Sentinels. The 'Amu River runs through the eastern part of Dinotopia, and has cut deep gorges through the Great Desert over the centuries, including the site of Canyon City. The Amu rises in the Backbone Mountains and runs south into Ancient Gorge and Red Rapid Canyon, where it empties into the World Beneath, becoming the Subamu River.