FOR IMMEDIATE RELEASE   Contact: Dave Thomas, VP Marketing and Planning

         (307) 432-7000

Great Lakes Aviation, Ltd. Reports June 2004 Traffic

CHEYENNE, Wyo., July 21, 2004 � Great Lakes Aviation, Ltd. (OTC Bulletin Board: GLUX � news) today announced preliminary passenger traffic results for the month of June.

Scheduled service generated 12,037,278 revenue passenger miles (RPM�s), a 7.7 percent increase from the same month last year.  Available seat miles (ASM�s) increased 2.9 percent to 27,706,096. As a result, load factor increased 1.9 points to 43.4 percent.  Passengers carried increased 7.3 percent to 43,398 when compared with June 2003.

For the six months ending June 30, 2004 compared to the same six month period in 2003, revenue passenger miles (RPM�s) increased 20.5 percent to 64,984,934 while available seat miles (ASM�s) increased 3.8 percent to 165,223,702, resulting in a load factor of 39.3 percent for the year 2004 compared to 33.9 percent for the same six month period in 2003.  The company carried 233,124 revenue passengers for the six month period ending June 30, 2004, an 18.9 percent increase on a year over year basis.

JUNE AND YEAR TO DATE STATISTICS

     June 2004 June 2003  Change

Passengers Enplaned  43,398   40,435  7.3%

Revenue Passenger Miles (000) 12,037   11,180    7.7%

Available Seat Miles (000) 27,706   26,918  2.9%

Load Factor    43.4%   41.5%   1.9 points

     YTD 2003  YTD 2002  Change

Passengers Enplaned  233,124  195,989 18.9%

Revenue Passenger Miles (000)  64,985  53,946  20.5%

Available Seat Miles (000) 165,224  159,181 3.8%

Load Factor    39.3%   33.9%   5.6 points

Great Lakes is providing scheduled passenger service at 36 airports in ten states with a fleet of Embraer EMB-120 Brasilias and Raytheon/Beech 1900D regional airliners. A total of 186 weekday flights are scheduled at three hubs, with 176 flights at Denver, 4 flights at Minneapolis/St. Paul, and 6 flights at Phoenix. All scheduled flights are operated under the Great Lakes Airlines marketing identity in conjunction with code-share agreements with United Airlines and Frontier Airlines at the Denver International Airport hub.

Additional information is available on the company web site that may be accessed at www.greatlakesav.com