Summer is prime national park season — long days, full wildflower blooms, and accessible high-altitude trails that are buried under snow the rest of the year. The tradeoff is crowds. These fifteen parks are worth dealing with those crowds, and for each one we've included the best strategies for avoiding the worst of them.
1. Zion National Park, Utah
Zion's slot canyons, the Virgin River Narrows, and the sheer sandstone walls of Angels Landing make it one of the most photogenic places on earth. The Narrows (wading upriver through the Virgin River canyon) is best from late June onward when the water is warm enough to wade comfortably. Beat the crowds by starting at the Temple of Sinawava trailhead before 7 AM — by 9 AM the shuttle lines are 45 minutes long. The West Rim Trail offers a full day of solitude that most day visitors skip entirely.
For more on this topic, see our guide on island hopping in greece: the perfect 10-day route.2. Rocky Mountain National Park, Colorado
Trail Ridge Road — the highest paved through-road in the US at 12,183 feet — typically opens fully in late May and closes in October. The alpine tundra along the ridge hosts pika, marmots, and summer wildflower meadows above treeline. Come on weekday mornings and park at the Bear Lake Road corridor before 8 AM to avoid the mandatory reservations that kick in after that time.
3. Acadia National Park, Maine
Maine's only national park sits on Mount Desert Island and combines rocky coastline, summit carriage roads, and the famous Jordan Pond House (popovers and tea since 1895). Cadillac Mountain — the first place in the eastern US to see sunrise from late October through early March — gets very crowded in summer; the sunrise reservation system ($6 per vehicle) is essential. The park is most beautiful in September when the crowds thin and foliage begins.
4. Glacier National Park, Montana
Going-to-the-Sun Road is one of the most spectacular drives in North America, crossing the Continental Divide at Logan Pass (6,646 feet). Vehicle reservations are required from late May through September — they sell out within minutes of release in January, so set a calendar reminder. The Highline Trail from Logan Pass is a 11.8-mile traverse along the Garden Wall with near-constant wildlife sightings: mountain goats, bighorn sheep, and the occasional grizzly on the slopes below.
5. Olympic National Park, Washington
Three distinct ecosystems — temperate rainforest (Hoh Rain Forest), rugged Pacific coastline (Ruby Beach, Rialto Beach), and glaciated peaks (Hurricane Ridge) — make Olympic the most ecologically diverse park in the lower 48. The Hoh Rain Forest receives 140 inches of rain annually and the resulting moss-draped Sitka spruce forest feels ancient and otherworldly. Summer is the driest season here (relative term — pack waterproof layers regardless).
6. Grand Teton National Park, Wyoming
Adjacent to Yellowstone and often overshadowed by it, Grand Teton arguably has more dramatic scenery: the Teton Range rises abruptly from the flat Jackson Hole valley with no foothills to soften the transition. The Jenny Lake loop trail (7.1 miles) and the approach to the Grand Teton itself (requires technical climbing permits) are summer highlights. Sunrise at Oxbow Bend — a classic reflection shot of Mount Moran in the Snake River — is best in June before the light shifts.
7. Yellowstone National Park, Wyoming
The world's first national park remains extraordinary. Old Faithful erupts approximately every 94 minutes, but the less-visited thermal features — Grand Prismatic Spring's rainbow bacteria mats, the bubbling mud pots at Fountain Paint Pot, the electric-blue Morning Glory Pool — are equally impressive. Book accommodation inside the park (Yellowstone Lodge, Old Faithful Inn) up to 13 months in advance; outside lodging in West Yellowstone or Gardiner is more available but adds commute time.
8. Great Sand Dunes National Park, Colorado
North America's tallest sand dunes (up to 750 feet) rise against the Sangre de Cristo Mountains in the San Luis Valley. The dunes are surrounded by a seasonal creek (Medano Creek) that flows in May–June, making it possible to splash through the water before climbing the dunes. This is Colorado's least-visited major park — you can often find stretches of dune completely to yourself even in July.
9. Congaree National Park, South Carolina
The largest intact expanse of old-growth bottomland hardwood forest in the southeastern US, Congaree is one of the most undervisited national parks in America despite being less than 30 minutes from Columbia, SC. The ancient loblolly pines and bald cypress trees dwarf visitors on the elevated boardwalk trail. In late May and early June, synchronized fireflies (Photinus carolinus) perform their light shows here — one of only a handful of places on earth where this happens.
10. Isle Royale National Park, Michigan
Accessible only by ferry or floatplane from Houghton or Copper Harbor, Michigan (or Grand Portage, Minnesota), Isle Royale is the least-visited national park in the lower 48 by total visitors — around 25,000 annually, compared to Zion's 4.7 million. The island sits in Lake Superior and has no roads, no cars, and no cell service. The Greenstone Ridge Trail (40 miles, 4–6 days) offers pure wilderness backpacking with wolves and moose as the primary wildlife.
11. Capitol Reef National Park, Utah
The often-overlooked member of Utah's Mighty Five, Capitol Reef is the least crowded of the group and arguably the most geologically interesting. The Waterpocket Fold — a 100-mile monocline wrinkle in the earth's crust — creates a landscape of white domes, red canyons, and a historic fruit orchard (Fruita) that visitors can pick from in season. The park sees roughly 1.4 million annual visitors versus Zion's 4.7 million.
12. Banff National Park, Canada
Canada's oldest national park ($10.50 CAD daily pass) is home to Lake Louise, Moraine Lake, and the Icefields Parkway — one of the world's most scenic drives. Moraine Lake Road now requires a shuttle reservation from May through October due to overwhelming demand; book via the Parks Canada reservation system at 8 AM Mountain Time on the release date in April. The Valley of the Ten Peaks behind Moraine Lake is worth every logistical hurdle.
13. Torres del Paine National Park, Chile
The granite towers and turquoise lakes of Torres del Paine in Chilean Patagonia are a bucket-list destination. The W Trek (5 days) and O Circuit (8 days) require advance refugio or camping reservations — often booked out by November for the following December–February summer season. Book at fantasticosur.com and verticepatagonia.cl. The park entrance fee is 21,000 CLP (approximately $22 USD) per person in peak season.
14. Jiuzhaigou Valley, China
A UNESCO World Heritage Site in Sichuan Province, Jiuzhaigou's series of multi-colored lakes — fed by calcium carbonate deposits that refract light to produce vivid blues, greens, and turquoise — are unlike anything in the Western national park system. The park recovered from a 2017 earthquake and reopened with improved infrastructure. Entry is 220 CNY ($30 USD) with an additional 90 CNY shuttle bus inside the valley; the best light is in the morning before noon.
15. Plitvice Lakes National Park, Croatia
Sixteen terraced lakes connected by travertine waterfalls in central Croatia. UNESCO-listed since 1979, Plitvice sees over 1.4 million visitors annually — but the timed entry system (book at np-plitvicka-jezera.hr) keeps the wooden boardwalk trails manageable. Early July sees waterfalls at full summer flow. The park is best visited mid-week in late June or early September to avoid weekend coach tour groups.