"I am committing to Wyoming," he told Scout.
Why the Cowboys? Mack said he likes the make up of their program and recent program success.
"Wyoming recently won the Mountain West Conference, had a first round draft pick and has past coaches presently coaching in the NBA," Mack said in a text message.
"The conference has a great west coast schedule, including UNLV, where I grew up first nine years of my life and still have family."
Mack took his official visit to Wyoming in late August. He selected the Cowboys over interest from Georgia, Villanova and St. Louis.
"Coach Edwards is a two time NCAA champion while at Kentucky, a great player, and a coach who I can learn a lot from," he added. "Coach Edwards can and wants to help me get to the next level after college."
With the Mack pledge, Wyoming now holds commitments from a trio of 2017 recruits. He joins a class that also consist of Hunter Thompson and Hunter Maldonado.