Imagine you are taking a cross-country trip whose route goes through the southern half of Oklahoma. As you leave Arkansas and enter Oklahoma, which mountain area will you encounter first?

The Ouachita Mountains extend across western Arkansas into southeastern Oklahoma, so they are the mountain area you encounter when crossing from Arkansas into southern Oklahoma. The Wichita and Arbuckle mountains are farther west in Oklahoma. The correct choice is Ouachita.

AI-written and checked against the verified answer.