Who was the regular season winner of the 1999 Big Sky Men's Basketball Tournament was the conference tournament?
CREATE TABLE "table1_29146083_3" (
  "conference" text,
  "regular_season_winner" text,
  "conference_player_of_the_year" text,
  "conference_tournament" text,
  "tournament_venue_city" text,
  "tournament_winner" text
);
SELECT "regular_season_winner" FROM "table1_29146083_3" WHERE "conference_tournament"='1999 Big Sky Men''s Basketball Tournament';