MidAmerica St. Louis Airport - Careers MidAmerica Airport supports a variety of good-paying careers, both through St. Clair County and its aviation partners. No career opportunites available at this time. St. Clair County Careers Find your next job at St. Clair County. More Information Careers Find your next job at the TSA. More Information Careers Find your next job at Boeing. More Information Careers Find your next job at Allegiant. More Information