Most national parks are crowded, and some are even requiring reservations. Once fall arrives, the visitor numbers at some of the parks plummet.

These include Great Smoky Mountains National Park and Acadia National Park in Maine, where you want to stand in line to enjoy Cadillac Mountain.

Out west, the Grand Teton National Park is best seen between early September through mid-October, and don’t miss the golden aspen trees in the Rocky Mountain National Park. The show starts in mid-September. You may still have to make some reservations, but you enjoy a less crowded experience.