Pre-1937 gambling in Montana was all technically illegal (though rarely enforced).
1937-1950, gaming was okay as long as it was licensed locally.
1950-72, gambling was illegal.
1973, gaming was legalized state-wide (only live poker, live keno, video poker, video keno):
only bars can be licensed for gaming
no more than 20 machines may be located at any licensee
there are many more "casinos" with machines only, than have live poker
there is no 24-hour gaming in Montana
most live poker games are open only on Friday and Saturday nights
some live poker games are open on more than just two days a week, but virtually all begin in the evening or late afternoon

Michael