Reno Air Races
Reno Air Races is an annual event taking place at the Reno Stead Airport (4SD) in Nevada, USA. Pilots are competing of who is able to complete a course in shortest time. The race includes multiple aircraft classes, each having its own course.
On this site you'll find all aircraft classes and corresponding course maps. As you'll see on the maps the runways, taxiways, and pylons serves as important landmarks of the courses. It's all part of the default scenery of FS2004 and FSX. Print the maps and try to complete the races.
Also see EAA AirVenture Oshkosh - another US flight event.
Thanks to Anthony Lynche for pointing out this place.