Portland International Raceway opened in 1961 on the former location of the city of Vanport, which was destroyed by the Memorial Day 1948 flood.
The 12-turn, 1.964-mile natural road course is relatively flat but contains several spots for passing opportunities, including a quick chicane at the end of the frontstretch, a hard-braking right-hander (Turn 7) leading onto the sweeping backstretch, and a three-turn complex leading back onto the fronstretch.
Al Unser Jr. won the first INDYCAR SERIES race in 1984. In 1997, the race set the now current all-time record for the closest two-car and closest three-car finish in INDYCAR SERIES racing history on a road course. Mark Blundell beat second-place Gil de Ferran by 0.027 of a second, and beat third-place Raul Boesel by 0.055 of a second, in a three-wide finish.