Wikipedia
WWSN (97.5 FM, "Sunny FM") is a radio station broadcasting an Adult Contemporary format. Licensed to Whitehall, Michigan, the station serves the Muskegon, Michigan market. The station's programming is derived from Cumulus Media Networks' Hits & Favorites format. It is heard as far Grand Rapids, Michigan, east Of US-131, and it experiences interference from WJIM-FM from Lansing. The station began broadcasting in 1991 as WPBK-FM with a satellite-fed country format from Unistar Radio Networks, and became WEFG-FM ("Frog") soon afterward. In 1995, WEFG's format changed to a 1970s-based classic hits format (as Eagle 97.5) satellite-fed from Westwood One. In 1999 Westwood One discontinued its 1970s hits format in favor of Rhythmic Oldies (tagged as "Groovin' Oldies"), and WEFG continued with this format until switching back to country (as "Kickin' Country") in 2002 and then to sports in 2005.
On December 14, 2010, just four days after it was announced that Clear Channel/Muskegon would replace WSHZ's Adult Contemporary format with WMUS and its Country format, WEFG dropped its Sports format as "The Champ" to pick up WSHZ's former one as "Sunny FM." This marks the second time since 1996 that another station has used the "Sunny" moniker other than WSNX, whose call letters once matched that handle. Sister station WVIB was known as Sunny FM for a time until 2004.