Tornadoes hit only flat sparsely populated areas?

Tornadoes hit on all surfaces. Many go unnoticed because they do not hit areas where people live. In the United States we have Tornado Alley...which pretty much runs straight up through the middle of the country. Much of this central region is flat, however there are elevations and these do get hit.

The tornadoes that hit in the early part of May in 1999 seemed to multiply as they destroyed much of the State of Oklahoma.Oklahoma City that had a tornado that a mile in width and stayed on the ground for over an hour destroying everything in its path.

Other major cities hit by tornadoes include Birmingham, Alabama; St. Louis, Missouri; and Fort Worth, Texas.