Bark-covered longhouses were an architectural style distinctive among the

wichita

Explanation:

Wichita is situated in a plain. Named after the first inhabitants of the area, the Wichitas Indians.

The first white man to see these Indians and make a record of them was Francisco Vazques de Coronado, a Spanish explorer. He explored southwestern America in the early 1500s looking for riches and found them in the Arkansas River area in 1541. And reported that "there were no more than twenty-five villages, the houses were thatched and bark-covered. All what they had was the tanned animal skin they killed, because the herds were close to where they lived in a fairly large river. They eat raw meat like the Cherechos and the Teyas."

i believe its the indians