Five people were killed in that area because of the twister, Smith said.
No houses were in the immediate vicinity, but other damage led officials to believe the area might be where the twister reached its peak, he said. Several vehicles were tossed hundreds of yards, a fully functional oil rig was blown over and trees were stripped of their bark.
Although the tornado has been rated EF5, Smith said the tornado did not sustain that intensity the whole time.
Two other tornadoes were rated EF4, one was an EF3, another an EF2 and the other an EF1. One twister is unrated.
This is the fifth EF5 tornado in the United States this year. Three EF5 twisters hit the South during an April outbreak and a tornado that devastated Joplin, Mo., also was rated EF5.
Before April, the last time an EF5 tornado occurred in the United States was in 2008 in Parkersburg, Iowa.