Never been near the Ozarks myself, I'm over in Glastonbury, but we get big cat reports here fairly regularly actually. Somerset and Wiltshire seem to be hotspots for it. Most people reckon they're descendants of animals released when the Dangerous Wild Animals Act came in back in '76, which is plausible enough I suppose.
Three times in one month is significant though. Worth keeping a camera ready if you can, even just your mobile. I know that sounds obvious but people always forget in the moment. The photographic evidence for these things is frustratingly poor across the board.
What size are we talking roughly? Like actual big cat big, or could it be a very large domestic gone feral? That distinction matters if you want anyone official to take it seriously.