I found this short video on YouTube while doing some random searches. It is an aerial view of parts of Amarillo along with some similar shots of the Palo Duro Canyon. Most people think Amarillo is completely flat, and the city itself is. But as soon as you leave to the north, you drive through the Canadian River breaks for an hour (all the way to Dumas) before you hit the high plains again.
The Palo Duro Canyon itself is the second largest canyon in the US (according to the State Park folks here). It is about 20 miles southeast of Amarillo, and only 8 miles east of my house.
Of course, no post on this topic would be complete without a link to Jason Aldean's song, Amarillo Sky. So here you go.