There are 3 NBA arenas in the Rocky Mountain region. The college venues, and I have listed 8, would host the group stage games, the opening round games. There are 4 other college arenas that would host the 2nd round games. The requirement is that each college arena has a capacity of at least 5,000. The larger college arenas host the 2nd round. One NBA arena would host all of the upper half of the final stage playoffs. One NBA arena would host the bottom half. The finals and consolation games would be hosted in the 3rd NBA arena.
Here are the venues I listed.
First round games 8 sites:
Arizona:
Walkup Skydome: Flagstaff
Colorado:
Clune Arena: Colorado Springs
Idaho:
ExtraMile Arena: Boise
Montana:
Dahlberg Arena: Missoula
Worthington Arena: Bozeman
New Mexico:
Dreamstyle Arena: Albuquerque
Utah:
Marriott Center: Provo
Wyoming:
Arena Auditorium: Laramie
2nd Round Venues 4 Sites:
Arizona:
McKale Center: Tuscon
Wells Fargo Arena: Tempe
Colorado:
CU Events Center: Boulder
Utah:
Huntsman Center: Salt Lake City
Quarter Finals and Semi Finals:
Pepsi Center: Denver
Talking Stick Arena: Phoenix
Marriott Center: Provo
Wyoming:
Arena Auditorium: Laramie
2nd Round Venues 4 Sites:
Arizona:
McKale Center: Tuscon
Wells Fargo Arena: Tempe
Colorado:
CU Events Center: Boulder
Utah:
Huntsman Center: Salt Lake City
Quarter Finals and Semi Finals:
Pepsi Center: Denver
Talking Stick Arena: Phoenix
Championship and Consolations Game Venue:
Vivint Smart Home Arena: Salt Lake City