On its finest days, summer feels like it could last forever. But, alas, all good things must come to an end. Or, when it comes to the seasons, sublimely shift into something new. As F. Scott Fitzgerald famously said, “Life starts all over again when it gets crisp in the fall.”

Deciduous trees know this best. Signaled by autumn’s softer temps and shortening days, they stop photosynthesizing and, in preparation for winter, draw nutrients from their leaves into their roots. Glorious greens, colored by chlorophyll, give way to yellow xanthophyll and orange carotenoid, pigments previously concealed. Deeper autumn days spur additional chemical processes that rouse red and purple pigments called anthocyanins. In lay terms, trees don new clothes and, in the process, put on one of nature’s finest and most flamboyant shows.

Yellow aspen trees in autumn, Colorado

Quaking aspen tree bark contains a high amount of chlorophyll. Beneath the bark is a thin green photosynthetic layer that allows the tree to create sugars and grow when other deciduous trees would otherwise be dormant.

Unfortunately, climate change is warming our autumns, and with it, disrupting both the timing and length of this annual display. There’s good news, however. Fall colors and conservation go hand in hand at Natural Habitat Adventures. Crafted in concert with our partner, World Wildlife Fund, our tours are 100% carbon neutral, and our eco-first Expedition Leaders all know the best places and times to experience peak fall foliage.

Bonus: From coastal Maine and Quebec to California’s Yosemite Valley, each of the following leaf-peeping adventures travel in small groups and swap heavily touristed tracks for secret, off-the-beaten-path spots so autumn’s splendor can truly shine.

Whether you’re planning ahead for next year or angling for a last-minute autumn excursion, now’s the best time to book your tickets. So, break out those merino wool sweaters and top off your thermos with hot cider. It’s time to go leaf-peeping.

1. Maine: See Peak Views in the Pine Poplar Tree State

Maine may be known as the Pine Tree State, but come autumn, the fiery poplars, beeches, maples and oaks that help define its deciduous forests all lobby fiercely for a moniker change. Nat Hab travelers can see them make their case on a seven-day Maine Coastal Explorer. Take in the colors while staying in a 200-year-old farmhouse turned boutique inn in Bangor, sailing aboard a historic windjammer in Camden’s Penobscot Bay, and strolling along the sylvan shorelines of Deer Isle. The “Maine” event: leaf peeping within the 47,000 protected acres of woodlands, mountains, lakes and coastlines that comprise Acadia National Park.

Maine coastal explorer autumn foliage white bridge and cottage over brook with red orange yellow trees peaceful zen

© Michelle Beebe

More Local Color: Look for weathered, whitewashed barns while meandering on Highway 1 along Penobscot Bay and the Blue Hill Peninsula; multihued buoys during a cruise around Mount Desert Island aboard a working lobster boat and—even better—bright crimson lobsters while dining at Deer Isle’s eighteenth-century Pilgrim’s Inn; and a pretty pink sunrise lighting up Bar Harbor from atop Cadillac Mountain, Acadia’s highest peak.

2. Quebec: Get Festive in French Canada

The provenance of Cirque du Soleil and host to 500-plus year-round festivals, the Canadian province of Quebec has a natural penchant for spectacle. This includes its vibrant fall foliage, which takes center stage each September and October. Nat Hab’s eight-day Whales and Nature Trails of Quebec tour takes in the performance at some of the province’s premier venues, including Saguenay Fjord, Hautes-Gorges-de-la-Rivière-Malbaie, Grands-Jardins and Jacques-Cartier national parks, along with Saguenay-St. Lawrence Marine Park. Sugar maples, ashes and yellow birches are among the stars that headline the annual event.

Hiking in Quebec Canada in the fall time river and forest views beautiful autumn foliage and mist over the mountains

© Judy Wilson

More Local Color: Look for blue whales (along with humpback, beluga, minke and more) during private whale-watching tours aboard Zodiacs in Saguenay-St. Lawrence Marine Park; gray wolves in Grands-Jardins and golden eagles in Hautes-Gorges-de-la-Rivière-Malbaie; and variously colored boutiques while wandering the cobblestone streets of Old Quebec, a UNESCO World Heritage site.

3. Vermont: Hop on that Bike and Ride

This is how we roll in the Green Mountain State: a private four-day bike tour amid leaf-peeping’s peak. Led by seasoned guides at Duvine, one of Nat Hab’s travel partners, cyclists hop on their choice of road, hybrid or electric bikes, select a route rating and then set out for stunning fall foliage on spins that wend, say, along the Ottauquechee River, through the historic Taftsville Covered Bridge and to Silver Lake for a timely dip. Along the way, well-deserved picnics at local farms, a tasting at the Plymouth Cheese Factory and hand-churned ice cream at the Barnard General Store await.

More Local Color: Look for fresh greens and other locally grown produce while dining at farm-to-table restaurants each evening; flavors like Blackbeary Wheat and Green Blaze IPA during a tasting at Long Trail Brewery in Bridgewater Corners; and the collection of colors and creativity on display at Simon Pearce’s glassblowing workshop in Quechee.

4. New York: Get Creative on the Hudson River

The Hudson, aka “America’s First River,” has autumn down to a fine art. Each fall, the waterway that inspired countless works by renowned mid-nineteenth-century landscape artist Thomas Cole and his contemporaries at the Hudson River School itself transforms into a painting, blazing with a beautiful palette of autumnal color.

Browse away on an eight-day Exploring the Hudson River: Fall Colors, Conservation & Creativity cruise with Nat Hab’s parent company, Lindblad Expeditions. Highlights include a tour of Cole’s home in Catskill and a stop in Hudson to learn about the sloop Clearwater and its same-named conservation group, co-founded by folk singer-slash-conservationist Pete Seeger.

More Local Color: Look for cerulean warblers and scarlet tanagers while kayaking in Constitution Marsh; Alexander Calder’s bright red, seventeen-foot Five Swords sculpture, among other impressive works at the open-air Storm King Art Center; and golden orbs shining from the Hudson’s string of historic lighthouses.

5. Wyoming: Have Yellowstone More to Yourself

How do we love Yellowstone National Park in the fall? Let us count the ways: 1. fewer visitors (summer crowds to America’s first—and most visited—national park have thinned out); 2. better photo ops (fewer people means less likelihood your Old Faithful pics will be photobombed); 3. increased wildlife sightings (many species are on the move while preparing for winter); and 4. brilliant bursts of fall colors (think red-leafed shrubs, golden aspens and bright yellow cottonwoods).

Nat Hab’s small-group, seven-day Hidden Yellowstone & Grand Teton Safari provides ample time—and space—to absorb it all within the park’s remote corners and off-the-radar spots.

Tetons in the fall Wyoming foliage autumn

Grand Tetons © Kurt Johnson

More Local Color: Look for brown bears along the shores of Yellowstone Lake; grey wolves in the Lamar Valley while getting the facts about this keystone species from wolf biologists; and millions of microscopic thermophiles that dye the park’s hydrothermal features in a kaleidoscope of colors.

6. Montana: Fall for Glacier National Park—Twice

Glacier’s so fond of fall, it celebrates the season twice. First, when aspens and cottonwoods flip their autumnal switch and illuminate the park’s lower elevations. And second, when its western larches, a deciduous conifer frequently found in the park’s western slopes, turn gold before shedding their needles ahead of winter.

Travelers can commemorate both transitions with aptly named Off the Beaten Path, one of Nat Hab’s travel partners, via a series of seven-to-seventeen-day small-group and custom-made adventures (activity levels range from “no sweat” to “high five!”) that also take in the best of the park’s glacier-carved mountains, gushing waterfalls and blue-green lakes.

Hiker Trekking on the Highline Trail in Glacier National Park in Montana in the Fall

More Local Color: Look for creamy white mountain goats while ascending Going-to-the-Sun Road; whitewater rapids on a rafting trip along the Middle Fork of the Flathead River; and yellow perch and rainbow trout while fly fishing Whitefish Lake.

7. Arizona & Utah: Be Illuminated in Bryce, Zion & the Grand Canyon

As if red rock country weren’t colorful enough, Bryce Canyon, Zion and Grand Canyon national parks really pop in autumn, punctuated by spectacular spurts from Gambel oaks, aspens and cottonwoods. Fall foliage, cooler temps and thinner crowds make autumn an optimal time to visit each park, particularly when enjoyed on Nat Hab’s eight-day Grand Canyon, Bryce & Zion national parks adventure. Our in-the-know Expedition Leaders seek out secret spots and less-visited lookouts so guests can, say, watch the sunset sparkle on the Grand Canyon’s South Rim in silence.

The Virgin River in Zion National Park during the fall season. Trees showing fall colors line the river.

Virgin River, Zion National Park

More Local Color: Look for multi-hued sedimentary layers in the Grand Canyon; Bryce Canyon’s pink sandstone hoodoos during a thrilling helicopter flight; and vibrant Navajo sand paintings and other authentic Native American crafts during a visit to the Cameron Trading Post on the Navajo Nation.

8. California: Get an Insider’s Look at Yosemite National Park

Yosemite will—we hope—forever be synonymous with its giant evergreen sequoias. (Great news: The park’s famous Mariposa Grove recently reopened after California’s Washburn Fire thankfully spared its 500 mature sequoias.) But we’re also partial to the park’s white alders, black oaks, bigleaf maples, dogwoods and other deciduous trees that make colorful cameos each autumn.

September departures on Nat Hab’s eight-day Insider’s Journey into Yosemite tour provide ample leaf peeping opportunities, along with time at iconic sites like Mariposa, trips to lesser-visited locales such as the Eastern Sierra for a stay at Mono Lake and talks with local experts, including noted climbers, a fire ecologist and a speaker from the Yosemite Conservancy.

More Local Color: Look for red foxes and black bears on a series of hikes; the Milky Way while stargazing in Yosemite Valley; and, at sunrise, Mono Lake’s tufa towers (limestone pinnacles) turning gold.

Yosemite National Park Valley at cloudy autumn morning from Tunnel View. Low clouds lay in the valley. California, USA