What St. Louis monument built to honor the westward expansion of the U.S. is near a 1.25 oval race track?
Gateway Arch: The Gateway Arch is a 630 ft monument in St. Louis in the U.S. state of Missouri. Gateway Arch:  Built as a monument to the westward expansion of the United States, and officially dedicated to "the American people," it is the centerpiece of the Jefferson National Expansion Memorial and has become an internationally recognized symbol of St. Louis, as well as a popular tourist destination.
i don't know