Which two states contain the bulk of the ozark mountains?

Missouri and Arkansas

Explanation:

The Ozark Mountains cover approximately 50,000 square miles in four states: Missouri, Arkansas, Oklahoma, and Kansas.

Most of those 50,000 square miles, however, are in just two states. According to the Missouri Department of Natural Resources, the forested mountain region takes up 33,000 square miles in Missouri and 13,000 square miles of Arkansas, with the remaining 4,000 split between Oklahoma and a very tiny sliver of Kansas.