LSSU has 3 DI men's ice hockey NCs (88, 92, 94). NDSU doesn't have any DI national championships.
Then again, men's ice hockey is played by less than 25% (or whatever it is) of the NCAA.
Alaska, for comparison, has 8 DI rifle NCs (94, 99, 00, 01, 02, 03, 04, 06). That's more than UND or LSSU, but since so few schools in the NCAA participate in it, you may or may not say that those are as significant as a football or basketball NC.