One of the best national parks for wildlife viewing in the US, Denali is home to Alaska's so-called 'Big 5': caribou, moose, wolves, dall sheep and, of course, grizzly bears. You can tour the park independently, but a ranger-led Discovery Hike allows you to leave the crowds behind and go "off-trail". A narrated bus tour is another popular option for wildlife viewing, and your expert naturalist will pause if they see a bear hulking at the roadside or a moose grazing in the brush. Be sure to follow the park's safety advice at all times.

Bull elk, bald eagles and a steady stream of waterfowl call this refuge in eastern Arizona home. Each July, bird lovers flock to the park for the High Country Hummers festival, during which the public can learn about a range of hummingbird species as they're banded and released back into the wild. Come in autumn or winter and you're more likely to catch a glimpse of elk amid the forestland or bald eagles circling overhead. Wildlife viewing points are stationed along each of the four hiking trails.

If you're dreaming of seeing a big cat, Arkansas might not be the first place you think to visit. But the well-respected Turpentine Creek Wildlife Refuge has been providing a home for "abandoned, abused and neglected big cats", from lions to leopards, since the 1970s. A range of tours give visitors insight into the site's lauded conservation work, and the Behind the Scenes Tour offers a glimpse of areas usually off-limits to the public. If you fancy extending your trip, you can even overnight here.

This vast area of protected California coastline is home to more than 1,500 species of flora and fauna, so it's an ideal place to get to grips with the Golden State's top wildlife. It's a mammoth site, encompassing some 80 miles of shoreline, and within its limits you'll find elephant seals, harbour seals, tule elk and even coyote and black bear. Spot frolicking seals from December through to March at Elephant Seal Overlook close to Chimney Rock and head to the Tule Elk Preserve at Tomales Point for a glimpse of these majestic mammals.

Eagle Landing is a fitting name for this 16-acre riverside park. In the colder months, bald eagles, and the occasional golden eagle, thrive in this slice of southern Connecticut, having escaped from the chill in the north of the state. For a great chance of a sighting, book onto one of River Quest's Winter Wildlife Eagles Cruises: you'll sail down the Connecticut River with expert naturalists who'll point your gaze in the right direction.

This giant national park comprises more than 1.5 million acres of wetland, so you'll need to plan carefully if you want to spot some wildlife. You'll find the American crocodile lurking in numerous parts of the park, including the Flamingo area, with its fascinating visitor centre, and on the sands of Cape Sable. Popular trails for wildlife spotting include the short Anhinga Trail, where you might also glimpse turtles and wildfowl. You could also head out on a kayak trail spooling out from the Flamingo Marina.

According to the World Wildlife Fund "nearly all species of sea turtle are classified as Endangered" and this sanctuary on Georgia's Jekyll Island is committed to the rehabilitation of these creatures. Describing itself a "working hospital", the centre conducts vital conservation work, as well as looking after injured reptiles and seeking to educate the public. Accompanied by expert staff, visitors can meet some of the "turtle patients", watch feeding time and learn from interactive exhibits.

This protected site on Hawaii Island is as rich in wildlife as it is in history. Green sea turtles are the park's most conspicuous reptile, sunning themselves on the shores or paddling in clear shallow waters. If you look closely you can also spot quick-footed geckos, as well as the occasional Hawaiian monk seal. In winter, you might see the crest of a humpback whale out at sea. Begin at the Hale Ho'okipa Visitor Contact Station, where staff can point you towards the best trail for nature viewing depending on the season.

Not to be confused with New York's Harriman State Park, this scenic area of forests and lakes is just a stone's throw from Yellowstone National Park – though you'll find its trails and woods to be much quieter. On the park's 22 miles of hiking routes, keep your eyes peeled for moose and elk peering from between the trees. Keen birders will also be in awe of the elegant trumpeter swans gliding on the lakes. To maximise your chances of an animal encounter, overnight in one of the yurts, cabins or bunkhouses here.

This protected area of swamps, wetland and cypress trees may look more at home in Louisiana or Florida perhaps. But you'll actually find it in southern Illinois. The migratory birdlife is a top draw here, and the prothonotary warbler, a dainty yellow songbird, is the most vocal of them all. A more secretive species is the endangered Indiana bat, but experts have found so-called 'maternity colonies' made up of female bats throughout the refuge during the summer months. The 1.5-mile Hickory Bottoms Trail leads visitors through forestland brimming with birds.

The Black Pine Animal Sanctuary is one of the most lauded sanctuaries in the Midwest. It's home to almost 100 rescued exotic animals, all of whom had been raised in captivity or displaced in some way. Lions, tigers and bears live out their days in the refuge, alongside smaller mammals like the kinkajou, a rainforest-dwelling relative of the racoon. A true sanctuary, the non-profit centre does not trade or breed its animals, and visitors can learn more about Black Pine's work on a guided tour.

The wondrous caverns in this national park are reason enough to visit, but the site holds some exciting wildlife too. Most intriguing of all is Mammoth Caves' bats – numbers of Indiana and gray bats at the park have fallen over the years, but staff are committed to protecting this endangered species. While the public aren't allowed into areas supporting bat colonies, you may well see a bat flit overhead as you take a ranger-led cave tour. Beyond the caves, coyotes, bobcats, groundhogs and more all live in the park.

Within the Jean Lafitte National Historical Park is the Barataria Preserve, a reptile-rich area of Louisiana wetlands. Here you'll find the formidable American alligator, soaking in the swamps or resting on the marshy banks. Also present are water snakes, tree frogs and more than 200 species of bird. Join a ranger-led Wetlands Walk to learn more about the preserve's critters, or book onto one of the park's Canoe Treks for an even closer look. 

Stellwagen Bank Marine Sanctuary is a protected area of water right at the mouth of the Massachusetts Bay. It's gloriously rich in sea mammals, from Atlantic white-sided dolphins to the harbour porpoise. But, most exciting of all is the presence of whales, from giant humpbacks to minke whales. The sanctuary welcomes a range of whale-watching tours on its waters, including Hyannis Whale Watcher Cruises, which come highly recommended. 

Many come to Isle Royale National Park, which floats in Lake Superior, in the hope of spotting a moose. The population of these gargantuan mammals is tightly bound to that of the gray wolf, the moose's only predator in the park. The wolf population here is currently extremely low, but park staff are working to reintroduce these predators onto the island over a period of several years. Top areas for a moose sighting include Washington Creek in the park's Windigo area, and the six-mile Minong Ridge Overlook Trail.

Named for its most fascinating residents, the Sandhill Crane National Wildlife Refuge occupies a sprawling area of pine savanna in southeastern Mississippi. The Mississippi sandhill crane is a critically endangered species – today, only 100 of these birds, with their long pointed beaks and conspicuous red crowns, remain, and all of them live in this refuge. A ¾-mile public nature trail winds its way from the visitor centre and, during the winter months, there are occasional tours to spots overlooking the cranes' favoured feeding sites.

The National Tiger Sanctuary in southwestern Missouri is committed to giving abused and/or abandoned big cats a safe refuge. Visitors to the site can learn more on a variety of tours, including the signature Awareness Tour, and are even afforded the chance to witness feeding time. Over the years the centre has also lobbied to protect animal rights in various capacities, including advocating for more stringent regulations for individuals who privately own big cats.

This fascinating not-for-profit centre takes in animals that are no longer able to survive in the wild and gives them a forever home. Residents at the Grizzly and Wolf Discovery Center include orphaned bears and wolves that were bred into captivity, as well as numerous non-releasable birds of prey. The site also carries out vital conservation work and seeks to educate the public about these compelling creatures. A range of interactive programmes and museum exhibits help visitors learn more about the animals tended to here.

Straddling the border between Arizona and Nevada, this National Recreation Area has incredible opportunities for wildlife viewing on either side of the state line. Mountain lions and coyotes pad through the park, but it's the curious desert bighorn sheep, Nevada's state animal, that really capture visitors' imagination. The species was once in serious decline, but reintroduction efforts have made some progress. They're nervous of humans and blend seamlessly with their surrounds, but keep your eyes peeled on one of the many hiking trails and you might just be lucky.

Celebrating its 80th birthday in 2019, the Edwin B. Forsythe Wildlife Refuge protects a great swathe of the New Jersey coast. You'll spot a variety of different creatures depending on the season. In summer, you might notice mud turtles in the freshwater ponds; in winter, monarch butterflies migrate right through the site. Whenever you visit, you'll see plenty of birdlife, from bald eagles in winter to ospreys in the spring. The Visitor Information Center and Nature Discovery Area is a great place to start.

The Carlsbad Cavern National Park comprises more than 119 caves – but it's equally famous for its huge colony of Brazilian free-tailed bats. These bats roost in the park's darkened caves, but from April through to mid-October, they exit the caverns nightly in their thousands, offering a spectacular show for the onlooking visitor. You can join a ranger on an evening Bat Flight Program to learn more about the phenomena.

Montauk Point State Park in Long Island is best known for its views of the striking Montauk Lighthouse – but in winter, there's another reason to visit this underrated spot. Each season, seals make a home of the rocky shoreline, and naturalist-led Seal Walks help you spot them. The walks are generally three-mile hikes along the beach and you'll be able to see up to four species of seal, while learning more about these adorable marine animals.

This refuge in Oklahoma's Wichita Mountains has some impressive numbers: the area supports 50 mammal species, 64 reptile species and 240 species of bird. Among the mammals are the American bison and the Rocky Mountain elk, both of which have been reintroduced after their populations in the park were diminished. Also keep your eyes peeled for little snapping turtles, yellow mud turtles and numerous species of lizard. Bugling Elk Tours run throughout the autumn and there are 16 different hiking trails to choose from. 

The Great Smoky Mountains National Park, with its epic panoramas of forested peaks, is certainly easy on the eye. It's also one of the USA's top spots for wildlife viewing, with elk, black bears and white-tailed deer all living among the wooded mountains. A popular viewing area is the Cataloochee Valley, since it's an open space within a park mostly shrouded by trees. Synchronous fireflies also attract visitors during their two-week mating season, which usually occurs between the end of May and mid-June.

You'll find the Hanging Rock Raptor Observatory perched in Monroe County's Peters Mountain. The rustic viewing tower, reached by a mile-long-hike, is a celebrated spot to take in birds of prey, with ospreys, falcons and eagles all regularly soaring past the deck. You've the best chance of seeing circling raptors in autumn, but even if you're not lucky, the mountain views alone are worth it. 

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More than 300 acres make up the remote Peninsula State Park, whose leafy expanse is filled with some of the state's top wildlife. Black bears make the occasional appearance, and the park's coyotes are elusive – but more likely to make themselves known are deers, racoons and porcupines. The park's summer nature programme is a boon for big and little wildlife lovers alike.

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America's first and most famous national park, Yellowstone stands head and shoulders about the rest when it comes to wildlife-viewing potential. More than 60 species of mammal wander its great expanse, including an estimated 690 grizzly bears. There are also bison and bighorn sheep, mountain lions and moose, and the elusive Canada lynx. The historic Fishing Bridge remains a favoured place for spotting grizzlies, while elk and bison are known to frequent the Mammoth Hot Springs area.

Of bison and bears: why Yellowstone reminds us of our place on the planet