Complex sentence: The Leadville Trail 100, an ultramarathon, takes place in and around Leadville along an 11.6 mile, two way non-motorized paved trail around the city.
Split into simpler sentences: The Leadville Trail 100, an ultramarathon, takes place in and around Leadville. The trail is an 11.6 mile, two way non-motorized paved trail around the city.