It's hard to tell from a photograph. It is either a decorative plaster, a paint technique or it's a wall paper. Sorry to be so vague but if I were betting man, I'd say that those walls have a paint technique applied to them.

There's a great finish called Venetian Plaster that's worth looking into.

If your walls are porous enough to grab it (there are also bonding primers), you can substitute the really expensive varieties of "stucco" or "fresco" applications with joint compound. It goes on as smoothly as one wants, and leaves as much irregularity as one wants for the light or the antiquing coat to emphasize....I've used it in several fixer uppers we've lived in.

Should have added....after joint compound dries, prime, then paint.

which custom cabinet
maker in bozemon?