Park Jefferson Speedway is a dirt ractrack based on the north side of Sioux City, Iowa. Park Jefferson was founded in the mid 1980's by Ted Carlson as the cornerstone of his racing empire. Park Jefferson rose to prominence as one of the top racing facilities in the area, feauturing Super Late Models and also touring specials with Outlaw Sprintcars from the NCRA. In 2014, Park Jefferson Speedway came under the umbrella of AtoZ Promotions.

Park Jefferson Speedway is home to weekly IMCA Racing featuring 6 classes of IMCA Race Cars each and every Saturday spring, summer and fall. In addition, Park Jefferson hosts Championship Sprint Cars, Super Late Models and more.