leaf peeper
n. A person who, at the appropriate time during autumn, seeks out an area where many or most of the tree leaves have turned color.
Other Forms
Last Saturday, 13 tour buses lumbered through Montpelier, Vt., to Burr Morse's maple sugar farm…The maple sugar was a sidelight. These sojourners were roaming the roads in search of the Peak.

Never mind that the hour or day when a particular hillside might be totally aglow is as unknowable as a Zen koan. The quest is for the perfect moment — the exact time and location when a leaf peeper will encounter the height of foliage color and experience foliage ecstasy. The search for it captivates and hypnotizes peeping tourists beyond all reason. And in the fall they drive into the country in hordes.
—Penelope Green, “When Brightest Fall Reds Are Brake Lights Ahead,” The New York Times, October 11, 2002
1980 (earliest)
The summer tourist rush has ended, and there are no major holidays on the calendar, but motels, restaurants and roadways across much of New England are packed this time of year with the "leaf peepers." It's foliage season, a blazing rite of fall that makes hills, swales and hammocks look like…well, like a New England postcard, and draws multitudes to ooh, aah and snap photographs.
—Joanne D'Alcomo, “Thousands Come for Colorful New England Autumn,” The Associated Press, October 11, 1980
The unrelenting green of a large forest at the height of summer is a beautiful sight. But if those trees are part of what scientists called a "mixed hardwood" forest — maples, birches, beeches, sumacs, poplars, and more — then in fall the green gives way to stunning reds, crimsons, oranges, yellows and other colors that make even the plainest speakers stretch for the right fire metaphors. This waning of the green — essentially, a leaf's dominant green chlorophyll dries up, exposing the other leaf pigments that were there all along — is big business, bringing in an estimated U.S.$8 billion annually in New England alone. This money is injected into the local economies by foliage traffic: the throngs of leaf peepers who set out on autumnal car, bus, and walking tours in search of the spectacular. There are even pro peepers who start in eastern Canada in September and follow the changing foliage south, ending up in the Carolinas and Georgia in late October or early November.