Flight Chicago, IL - Portland, OR prices from $99.67

Allegiant Air is an American low-cost airline that operates scheduled and charter flights. It was founded in 1997 and is headquartered in Las Vegas, Nevada. The airline operates flights to over 120 destinations across the United States, including popular vacation destinations such as Las Vegas, Orlando, and Myrtle Beach. Allegiant Air operates a fleet of Airbus A319, A320, and A321 aircraft, and offers a range of services including seat selection, priority boarding, and in-flight entertainment. The airline has been recognized for its low fares and customer service, and has won several awards for its performance and reliability.

Key Lime Air is a regional airline based in Denver, Colorado, that provides scheduled and charter flights to various destinations in the United States. The airline operates a fleet of turboprop aircraft, including the Fairchild Swearingen Metroliner and the Beechcraft 1900, which are known for their reliability and efficiency. Key Lime Air offers cargo services as well, transporting goods and packages for various industries, including medical, automotive, and aerospace. The airline has a reputation for providing safe, on-time, and cost-effective transportation solutions for both passengers and cargo.

Spirit Airlines is an American ultra-low-cost carrier that operates flights throughout the United States, the Caribbean, Mexico, and Central and South America. The airline was founded in 1983 and is headquartered in Miramar, Florida. Spirit Airlines is known for its low fares and no-frills approach to air travel, with passengers paying extra for amenities such as checked baggage, seat selection, and in-flight refreshments. The airline operates a fleet of Airbus aircraft and has a frequent flyer program called Free Spirit. Despite its low-cost model, Spirit Airlines has faced criticism for its customer service and fees.

United Airlines is a major American airline headquartered in Chicago, Illinois. It is one of the world's largest airlines, operating a comprehensive domestic and international network of flights. United Airlines operates a fleet of over 800 aircraft, serving more than 350 destinations in over 50 countries. The airline is a founding member of the Star Alliance, which is the world's largest airline alliance. United Airlines offers a range of services to its passengers, including in-flight entertainment, Wi-Fi, and a loyalty program called MileagePlus. The airline has a strong commitment to sustainability and has implemented various initiatives to reduce its environmental impact.

Sun Country Airlines is a low-cost American airline headquartered in Minneapolis, Minnesota. It was founded in 1982 and operates scheduled and charter flights to destinations across the United States, Mexico, Central America, and the Caribbean. Sun Country Airline's fleet consists of Boeing 737-800 and 737-700 aircraft, and it offers a variety of services including in-flight entertainment, Wi-Fi, and food and beverage options for purchase. The airline has a reputation for providing affordable fares and friendly service, making it a popular choice for leisure travelers. Sun Country Airlines is committed to safety, sustainability, and customer satisfaction.