Complex sentence: Since 1993, Lernerville has run the Sprints, Late Models, Modifieds and Sportsman divisions, thus being the only track in the country to run the "Big 3" (Sprints, Mods, and Late models).
Split into simpler sentences: Since 1993, Lernerville has run the Sprints, Late Models, Modfieds and Sportsman divisions. Thus, being the only track in the country to run the "Big 3", (Sprint, Mods, and Late models).