|Broadcast area||Portions of The San Gabriel Valley|
|Slogan||Music and More|
|Callsign meaning||Mt. San Antonio College|
|Owner||Mount San Antonio College|
KSAK is the FM campus radio station of the Mt. San Antonio College in Walnut, California. The station once broadcast a professionally programmed format designed to represent what actually goes on in the radio industry, instead of alternative programming typically found on most college radio stations. Broadcasters and producers from local commercial radio stations teach classes at the college and supervise students who produce and announce news and music programming. The station broadcasts music in alternating blocks of hip-hop, alternative rock, and pop music, interspersed with news and public service announcements.
In fall 2011, the station was rebranded as "90.1 FM MtRock" after a management change at the college. The station is currently a rock format, playing rock from 1960 to today, as well as music from local Los Angeles artists and is operated by students at the college.