There are a lot of JACK FMs in the US with many different owners:
Kodiak, Alaska KRXX 101.1 FM
Fresno, California KFJK 105.9 FM
Los Angeles, California KCBS-FM 93.1 FM
Palm Springs, California KAJR 95.9 FM
Redding, California KESR 107.1 FM
Sacramento, California KQJK 93.7 FM Sale to Clear Channel Communications pending
San Diego, California KFMB-FM 100.7 FM
Susanville, California KLZN 96.3 FM
Aspen/Vail, Colorado KKCH 92.7 FM
Denver, Colorado KJAC 105.5 FM/102.3 FM now on 102.3 FM (as of September 1, 2008)
Hayden/Craig/Steamboat Springs, Colorado KIDN 95.5 FM/95.9 FM
Vero Beach, Florida WJKD 99.7 FM
Chicago WJMK 104.3 FM
Norridge, Illinois WRHS 89.7 FM
Evansville, Indiana WEJK 107.1 FM
Sioux City, Iowa KZSR 102.3 FM
Lake Charles, Louisiana KBIU 103.3 FM
Baltimore, Maryland WQSR 102.7 FM Sale to Clear Channel Communications pending
Minneapolis-St. Paul, Minnesota KZJK 104.1 FM
Jackson, Mississippi WWJK 94.7 FM
Columbia/Boonville, Missouri KWJK 93.1 FM/103.5 FM
Kansas City, Missouri KCJK 105.1 FM
West Plains, Missouri KSPQ 93.9 FM
Missoula, Montana KYJK 105.9 FM
Buffalo, New York WBUF 92.9 FM
Las Vegas, Nevada KKJJ 100.5 FM
Oklahoma City, Oklahoma KOJK 97.3 FM
Pierre, South Dakota KLXS-FM 95.3 FM
Chattanooga, Tennessee WHJK 95.3 FM
Knoxville/Maryville, Tennessee WQJK 95.7 FM
Nashville, Tennessee WCJK 96.3 FM
Amarillo, Texas KPRF 98.7 FM
Bryan/College Station, Texas KJXJ-FM 103.9 FM
Dallas, Texas KJKK 100.3 FM
Houston/Beaumont-Port Arthur, Texas KHJK 103.7 FM
Longview/Tyler, Texas KAJK-FM 99.3 FM
Lubbock, Texas KJDL-FM 105.3 FM
McAllen KJAV 104.9 FM
Midland/Odessa, Texas KFZX 102.1 FM
San Antonio, Texas KJXK 102.7 FM
Victoria, Texas KTXN 98.7
Salt Lake City/Provo, Utah KJQN/KNJQ 103.1 FM/105.1 FM
Seattle, Washington KJAQ 96.5 FM
Wheeling, West Virginia WYJK-FM 100.5 FM