Donald Blakeslee says he's found Etzanoa, a long-lost city.

Etzanoa is the second-biggest settlement of Native Americans found in the United States, Blakeslee said. Now it is the known location of a 1601 battle pitting outnumbered Spaniards firing cannons into waves of attacking Indian warriors.

Etzanoa has been a mystery for 400 years. Archaeologists could not find it. Historians thought reports of a permanent settlement with 20,000 Native Americans in it were exaggerated.

But in Arkansas City, at the confluence of the Walnut and Arkansas Rivers, Blakeslee, an anthropologist and archaeologist at Wichita State University, has found evidence of a town stretching across thousands of acres of bluffs and rich bottomland along two rivers. What clinched it was the discovery, by a high school student, of a half-inch iron cannon ball.