CHEYENNE, Wyo., Sept. 12 /PRNewswire-FirstCall/ -- Great Lakes Aviation, Ltd. (OTC:GLUX) (BULLETIN BOARD: GLUX) today announced preliminary passenger traffic results for the month of August. Scheduled service generated 10,549,000 revenue passenger miles (RPM's), a 18.0 percent decrease from the same month last year. Available seat miles (ASM's) decreased 14.2 percent to 25,231,000. As a result, load factor decreased 1.9 points to 41.8 percent. Passengers carried decreased 14.7 percent to 40,052 when compared to August 2004. Preliminary revenue per available seat mile (RASM) increased 16.6 % from 23.61 cents to 27.54 cents. For the eight months ending August 31, 2005 compared to the same eight month period in 2004, revenue passenger miles (RPM's) decreased 15.2 percent to 77,054,000 and available seat miles (ASM's) decreased 17.0 percent to 185,993,000, resulting in a load factor of 41.4 percent for the year 2005 compared to 40.5 percent for the same eight month period in 2004. The company carried 289,322 revenue passengers for the eight month period ending August 31, 2005, an 11.6 percent decrease from the prior year. Preliminary revenue per available seat mile (RASM) increased 16.0% from 21.85 cents to 25.34 cents on a year-over-year basis. AUGUST 2005 AND YEAR TO DATE STATISTICS August 2005 August 2004 Change Passengers Enplaned 40,052 46,979 (14.7%) Revenue Passenger Miles (000) 10,549 12,863 (18.0%) Available Seat Miles (000) 25,231 29,423 (14.2%) Load Factor 41.8% 43.7% (1.9) points RASM (cents) 27.54 23.61 16.6% YTD 2005 YTD 2004 Change Passengers Enplaned 289,322 327,244 (11.6%) Revenue Passenger Miles (000) 77,054 90,821 (15.2%) Available Seat Miles (000) 185,993 224,011 (17.0%) Load Factor 41.4% 40.5% 0.9 points RASM (cents) 25.34 21.85 16.0% Great Lakes is providing scheduled passenger service at 39 airports in ten states with a fleet of Embraer EMB-120 Brasilias and Raytheon/Beech 1900D regional airliners. A total of 201 weekday flights are scheduled at three hubs, with 176 flights at Denver, 10 flights at Albuquerque, and 25 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 and Phoenix International Airport hubs. Additional information is available on the company web site that may be accessed at http://www.greatlakesav.com/ Contact: Michael Matthews, VP Finance/CFO (307) 432-7000 DATASOURCE: Great Lakes Aviation, Ltd. CONTACT: Michael Matthews, VP Finance/CFO of Great Lakes Aviation, Ltd., +1-307-432-7000 Web site: http://www.greatlakesav.com/

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