WBSF (branded CW 46) is the CW-affiliated television station for the Flint/Tri-Cities market that is licensed to Bay City. Owned by Cunningham Broadcasting, it is operated by Sinclair Broadcast Group, making this station a sister station to NBC affiliate WEYI-TV (owned by Howard Stirk Holdings) and Fox affiliate WSMH. The two stations (WEYI & WBSF) share studios on West Willard Road in Vienna Township along the Genesee and Saginaw County line.
It broadcasts a high definition digital signal on UHF channel 46 from a transmitter located on Becker Road in Robin Glen-Indiantown, in Buena Vista Township, east of Saginaw. The station can also be seen on WEYI's second digital subchannel (virtual channel 25.2) from its Vienna Township transmitter.
A permit was issued by the FCC for a new station on channel 46 in Bay City to Vista Communications Group in late 2003. The station is expected affiliate as Flint/Tri-cities market's WB.
On October 1, 2004, the station's construction permit was approved. In 2004, Barrington launched WB affiliate WBSF on cable and on WEYI's second digital subchannel. On February 2, 2005, the FCC transferred the permit to Acme Television then to Barrington Broadcasting.
With the merger of The WB and UPN to become The CW, WBSF became the area's network affiliate in September 2006 when the channel began broadcasting over the air. Because of this, a chance existed that WKBD (which along with WBKP are the only other over-the-air CW affiliates in Michigan) would be dropped from this market's cable systems as both WBSF and WKBD would be CW affiliates. However, in the case of Midland, two CBS affiliates do coexist on the same cable system. This occurred on Charter's Tri-Cities systems which replaced WKBD with MyNetworkTV affiliatwe WNEM-DT2 that became the new home of Pistons basketball that year. As a result of the network change, WBSF rebranded from "Mid-Michigan's WB" to "CW 46 Mid-Michigan". However, its call letters were not changed as the "B" in the calls also stands for Bay City which is the station's city of license. "S" and "F" stand for Saginaw and Flint, respectively. WBSF signed-on its analog channel on September 13, 2006 although it continues to be seen on WEYI-DT2. As such, it is the only full-power television station to be built and signed-on by Barrington Broadcasting although Barrington acquired its construction permit from ACME Communications before construction began.
In June 2008, WBSF received its Construction permit for its digital facilities with the station switching from analog to digital broadcasting on June 12, 2009.
On February 28, 2013, Barrington announced that it would sell its entire group, including WBSF and WEYI, to Sinclair Broadcast Group. However, due to FCC duopoly regulations, since Sinclair already owns Fox affiliate WSMH, Sinclair will transfer the license assets of WBSF to Cunningham Broadcasting and of WEYI to Howard Stirk Holdings (owned by conservative talk show host Armstrong Williams). WSMH will take over the operations of both WBSF and WEYI through local marketing agreements when the deal is completed. The sale was completed on November 25.
WBSF has served as an alternate NBC affiliate. The station aired a WWE Saturday Night Main Event on tape delay in 2005 due to WEYI's Pistons coverage. In 2006, the channel aired an episode of Friday Night Lights (also on tape delay) due to WEYI's broadcast of the second Michigan gubernatorial debate. The station may air any preempted NBC program should the preemption occur on WEYI for a local special, breaking news story, or any other emergency.
WBSF once aired a weeknight newscast known as The 7 O'Clock News on CW 46 which was produced by WEYI. This production was canceled in April 2008. The station, being operated by Sinclair and a CW affiliate, may carry sports from Sinclair Networks' American Sports Network as it was slated for its CW or My Network TV affiliated stations.