Most of those Montana monoliths are natural.
They look nothing like the man made monoliths in the old world.
And none look like highly developed engineerin if by that you mean anything beyond neolithic. Stonehenge is impressive, as are the pyramids but both are neolithic or chalcolitic.
You’re welcome to your opinion, no matter how far off the evidence it is.
The many thousands of dolmens found around the world are anything but natural formations. The many walls constructed from large, rectilinear stones are far from “natural” (examples:
https://www.montanamegaliths.com/uploads/6/9/2/9/69295147/published/sage-wall-julie.jpg?1598642154 and https://www.soulask.com/wp-content/uploads/2018/02/1517506860_925_i-never-knew-that-russia-has-these-shocking-ancient-megaliths.jpg). Same for the huge zoomorphic shapes found in various places.
