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

       (307) 432-7000

Great Lakes Aviation, Ltd. Reports May 2004 Traffic

CHEYENNE, Wyo., June 17, 2004 � Great Lakes Aviation, Ltd. (OTC Bulletin Board: GLUX.OB � news) today announced preliminary passenger traffic results for the month of May.

Scheduled service generated 10,398,978 revenue passenger miles (RPM�s), a 1.3 percent increase from the same month last year.  Available seat miles (ASM�s) decreased 3.7 percent to 25,712,913. As a result, load factor increased 1.9 points to 40.4 percent. Passengers carried increased 3.4 percent to 38,000 when compared with May 2003.

For the five months ending May 31, 2004 compared to the same five-month period in 2003, revenue passenger miles (RPM�s) increased 25.6 percent to 52,947,206 while available seat miles (ASM�s) increased 4.0 percent to 137,517,606, resulting in a load factor of 38.5 percent for the year 2004 compared to 31.9 percent for the same five-month period in 2003. The company carried 189,726 revenue passengers for the five-month period ending May 31, 2004, a 22.0 percent increase on a year over year basis.

MAY AND YEAR TO DATE STATISTICS

     May 2004 May 2003 Change

Passengers Enplaned  38,000   36,744   3.4%

Revenue Passenger Miles (000) 10,399   10,266    1.3%

Available Seat Miles (000) 25,713   26,698    -3.7%

Load Factor    40.4%   38.5%   1.9 points

     YTD 2004 YTD 2003 Change

Passengers Enplaned  189,726 155,554  22.0%

Revenue Passenger Miles (000) 52,947   42,166  25.6%

Available Seat Miles (000) 137,518 132,263    4.0%

Load Factor    38.5%  31.9%    6.6 points

Great Lakes is providing scheduled passenger service at 37 airports in ten states with a fleet of Embraer EMB-120 Brasilias and Raytheon/Beech 1900D regional airliners. A total of 174 weekday flights are scheduled at three hubs, with 164 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 hub.

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