WCKL (97.9 MHz) is a non-commercial FM radio station licensed to Chicago, Illinois, featuring a Christian contemporary format via the K-Love network.

Owned and operated by Educational Media Foundation (EMF), WCKL serves the Chicago metro area with a transmitter located atop the John Hancock Center.

[9] When the contract with National ran out in the mid-1950s, WEHS simulcast the foreign language and Black programming of co-owned WHFC for six hours a day, the minimum broadcast time to keep the license.

[14] The station was also known as "the station with the girls and all that jazz",[15] as it featured all female DJs known as "Den Pals",[16] which included Yvonne Daniels, Danae Alexander, Cody Sweet, Penny Lane, Nancy Plum,[17] Connie Szerszen, known on the air as "Dawn", and Linda Ellerbee, known on the air as "Hush Puppy".

[19][23] In 1968, the station began airing a nighttime progressive rock program called Underground Den on weekends.

[3] The station adopted an album-oriented rock (AOR) format and was rebranded as "The Loop", referring to the nickname of Chicago's central business district.

[30][31] Jay Blackburn was Program Director and Tommy O'Toole served as the station's first morning host and was the first Loop DJ to sign on the air.

[32][34] The original Loop air staff included Tommy in mornings, William "Captain Billy" Martin in middays, Lester "Les" Tracy in afternoons, and Bob Shannon evenings.

[34] Other early Loop DJs included Greg Budell, Ford Colley, Don Davis, and Glory-June Greaif.

[34] Steve Dahl, who had been unemployed since WDAI (94.7 FM) went to a disco format in December 1978, began hosting mornings on March 19, 1979.

[45] A series of morning men including Matt Bisbee, Mark McEwen, and the team of R.J. Harris and Pat Still tried their hand until Jonathon Brandmeier was hired in late 1982.

[58][59] In the early 1990s, WLUP aired a popular television commercial featuring a fat man dubbed "Joey Bag O' Donuts" dancing.

[40] Shortly thereafter, Dahl moved to AM 1000, which had recently added ESPN sports programming and changed call letters to WMVP.

[77] In order to stay under federally mandated ownership limits, Evergreen opted to sell WLUP to Bonneville International in July.

[78][79] On July 21 at 5 a.m., after stunting with all-The Who songs as part of a Who concert that previous weekend, WLUP switched back to a rock format.

[83] During this period, full-time on air personalities included Byrd (now with WDRV Chicago), Steve Downes, Eddie Webb, Pete McMurray, Seaver, Cara Carriveau, Sari, and Mark Zander.

[84][85][86][87][88][89] In October 2004, Emmis Communications traded three of their stations in Phoenix to Bonneville for WLUP-FM and $70 million; the swap was completed in December of that year.

[93][94] In 2005, Emmis brought back Jonathon Brandmeier to do mornings on The Loop and hired Zakk Tyler to host afternoon drive.

[101] On June 21, 2011, Emmis announced that it would sell WKQX, sister station WLUP-FM, and New York's WRXP to Merlin Media, a group headed by former Tribune Company executive Randy Michaels.

[112][113] Another prominent Loop Rock Girl prior to the station's 2018 closure was April Rose Haydock, who also served in that role in 2007.

Cumulus stated that under the agreement, which carries a monthly fee of $600,000, the company had lost $8.4 million on the two Merlin stations.

The move gives EMF its second full-power outlet in Chicago; the organization also owns translators and lower-power stations in the market.

[116] On March 6, Cumulus ended manned operations on WLUP-FM and the entire air staff was dismissed; however, the Mancow show continued via its independent online streaming platform.

An automated playlist of music continued until March 10 at midnight, when EMF took control of the frequency from Merlin under a new LMA and assumed the K-Love schedule carried by future sister station WJKL (94.3 FM).

[117][118] The sale of WLUP-FM also ended the annual "Loopfest", a sponsored event the most recent version of which was planned for August 3, 2018 at Hollywood Casino Amphitheatre, with Lynyrd Skynyrd to support their final tour with .38 Special and the Marshall Tucker Band.

[119] Upon hearing the news of the sale, Steve Dahl pointed to WLUP-FM's legacy and heritage, saying: As I look back on my 40 years on the radio in this market, I am reminded almost daily of The Loop's impact not only my career, but also rock and roll history in Chicago, and around the world.

In a last jab at the impending transition to Christian music, WLUP-FM, after spending a majority of their final hour playing songs themed around farewells and/or departures, closed by playing, for their final block of music, "Shout at the Devil" by Mötley Crüe, "The Number of the Beast" by Iron Maiden, and (as Dahl suggested) "Highway to Hell".

In March 2021, WCKL-HD3 adopted the "Boost Radio" Christian pop/hip hop format from KXBS in St. Louis as part of an agreement between that station's owners and EMF, and began simulcasting on translator 97.5 W248BB.