2023 SPRING MACK DAYS MARCH 16 - MAY 13 UP TO (1) Tagged $10,000 fish; (3) $5,000; (5) $1,000; plus over (9,000) tagged Lake Trout ranging from $100 - $500. Flathead Lake $225,000 IN CASH + PRIZES ONED BY SANGHIONED PARKS Catch the $1,000 Fish! Sponsored by Bretz RV & Marine SPONSORED OF THE BY KIXOTE A People of Vision . LATHEAD RESERVATION For Rules, Prizes, Check-in Sites or to Register, go to: www.mackdays.com or call 675-2700 EXT. 7294 2023 SPRING MACK DAYS MARCH 16 - MAY 13 UP TO ( 1 ) Tagged $ 10,000 fish ; ( 3 ) $ 5,000 ; ( 5 ) $ 1,000 ; plus over ( 9,000 ) tagged Lake Trout ranging from $ 100 - $ 500 . Flathead Lake $ 225,000 IN CASH + PRIZES ONED BY SANGHIONED PARKS Catch the $ 1,000 Fish ! Sponsored by Bretz RV & Marine SPONSORED OF THE BY KIXOTE A People of Vision . LATHEAD RESERVATION For Rules , Prizes , Check - in Sites or to Register , go to : www.mackdays.com or call 675-2700 EXT . 7294