Where is an area called Tornado Alley located?

Tornado Alley is a colloquial term for the area of the United States where tornadoes are most frequent.

The term was first used in 1952 as the title of a research project to study severe weather in areas of Texas, Oklahoma, Kansas, South Dakota, Illinois, Iowa, Missouri, Nebraska, Colorado, North Dakota, Ohio, and Minnesota. It is largely a media-driven term although tornado climatologists distinguish peaks in activity in certain areas and storm chasers have long recognized the Great Plains tornado belt.

Although the official boundaries of Tornado Alley are not clearly defined, the main alley extends from northern Texas, through Oklahoma, Kansas, Nebraska, Missouri, Iowa, South Dakota, and North Dakota

States such as Minnesota, Wisconsin, Illinois, Indiana, and Ohio are sometimes included in Tornado Alley. Research suggests that tornadoes are becoming more frequent in the northern parts of Tornado Alley where it reaches the Canadian prairies.