Chaparral and Valley, former members of the Sunset Division, joined the league in the 1990s.
Sunrise Mountain's enrollment figures based on that reported by an independent source.
In June 2011, the NIAA's Southern Realignment Committee approved a realignment of Sunrise 4A Region, Sunset 4A Region and Southern 3A Region that would place 24 teams from Class 4A into Class 4A–Division I and 13 teams, including 3A members Boulder City, Moapa Valley and Virgin Valley, into Class 4A–Division II.
The Sunrise 4A Region sponsors thirteen sports divided into three seasons: Fall, Winter, and Spring.
There are seven prominent football rivals involving schools within the Sunrise 4A region; one, the Bone Game between Las Vegas and Rancho, is the oldest, continual football rivalry in the state, starting in the 1930s.