Tyler Melville added 15 points for the Big Green (6-13, 2-3), as the trio made 20 of 31 field goals. Mitola was 4 of 5 and Melville 3 of 4 from 3-point range.
Dartmouth finished 7 of 15 from 3-point range to 3 of 20 for the Lions (9-10, 1-4).
A 14-2 Columbia run erased an 11-point Dartmouth second-half lead. John Daniels' dunk with 2:41 remaining put the Lions ahead for the last time, 54-52.
Mitola responded with a free throw, a layup and a 3-pointer for Dartmouth.
Former Kentucky guard Ed Davender, the only Wildcat with at least 1,500 points and 400 assists, has died. He was 49.
Guard Naz Mitrou-Long, whose 2015-16 season ended in December due to hip problems, has been granted a hardship waiver for the coming season, Iowa State said.
As the Sooners look to life without superstar Buddy Hield and his sidekicks, it's clear their unseasoned players will need to grow up fast.