Spring is in the air, and campers and hikers around the country are ready to get outside to enjoy the many national and state parks the country has to offer. It's no coincidence that National Park Week starts on April 15, when weather in many parts of the country is finally warm enough for adventuring. It's also a great time to save some money. During both weekends of National Park Week (April 15-16 and 22-23), entry is free. Here are some of the best parks to visit in the spring.
ACADIA NATIONAL PARK, MAINE
Acadia National Park offers a broad network of hiking trails, from the relatively gentle Ship Harbor, a 1.2-mile loop of forest and shoreline, to the more strenuous 4.4-mile Cadillac North Ridge Trail, with its views of Frenchman Bay. For those who want a real challenge, there's the much steeper 4.6-mile Sargent Mountain trail. For hardy campers, Blackwoods Campground is open year-round and free from December to the end of March (the fee is $15 a night in April and $30 a night May to October).
ANZA-BORREGO DESERT STATE PARK, CALIFORNIA
Thanks to the drought-busting rainfall in California this year, many desert parks are experiencing a rare "super bloom" of wildflowers. Anza-Borrego, California's largest state park, is drawing record crowds eager to see the flowers, so plan to arrive early. Visitor center parking is $5.
ARCHES NATIONAL PARK, UTAH
Arches National Park is iconic for its arched rock formations set against desert cacti, mosses, shrubs, and trees. It also offers an extensive network of hiking trails for a variety of ability levels. Be aware, however, that the park is undergoing road construction this year, so check which trails are open before visiting. The Devils Garden Campground is also closed due to construction through Nov. 30, 2017. Entrance fees range from $10 for an individual on foot to $15 for a motorcycle with rider and passenger to $25 for a private car with passengers.
BIG BEND NATIONAL PARK
This West Texas national park has a number of unique attributes -- one being that it crosses the border of Texas into Mexico. Visitors can walk to Mexico through the park's Boquillas Crossing Port of Entry (with a passport). Backpackers can explore Big Bend, although they need to be well-prepared for heat and extreme conditions in late spring. There are three National Park Service-operated campgrounds in the park offering basic sites for $14 a night. Entrance fees are $12 for individuals, $20 for motorcycles, and $25 for vehicles.
BIGHORN CANYON NATIONAL RECREATION AREA
Stretching across 68,000 acres, this enormous park is so big it actually spills over the northern border of Wyoming into Montana. In addition to the bighorn sheep that are part of its name, the park includes Bighorn Lake -- a popular fly-fishing site -- and 28 miles of hiking trails. The entrance fee is $5 daily for everyone.
CARLSBAD CAVERNS, NEW MEXICO
Deep beneath the Chihuahuan Desert lies Carlsbad Caverns, which actually comprises more than 119 caves (and those are just the ones we know about). It's possible to take self-guided tours through the caves, but consider taking a ranger-guided tour (fees vary) to see more of the caverns. The basic entrance fee is $10 for adults, and children are free.
CUYAHOGA VALLEY NATIONAL PARK, OHIO
The only national park in Ohio, Cuyahoga Valley has 125 miles of hiking trails, many of which wind past waterfalls and cross streams and wetlands. Before visiting, check the online hiking guide and the current conditions page for closures. There is no entrance fee for this park.
DEATH VALLEY NATIONAL PARK, NEVADA
Despite the name, there is a lot of springtime desert life in Death Valley -- including snakes, salamanders, toads, and desert tortoises. Early spring is a good time to hike in the park, and visitors sometimes see wildflowers if it's been a rainy winter. Still, don't assume the weather will be cool -- temperatures can reach over 91 degrees in April. Note that a number of roads are closed due to recent floods. Weeklong entrance to Death Valley is $25 for vehicles, $20 for motorcycles, and $12 for individuals.
GRAND CANYON NATIONAL PARK, ARIZONA
Although Grand Canyon National Park is listed by the National Park Service as a single park, it's essentially two parks: the South Rim and the North Rim. Only the South Rim, which has limited hiking options but great views, is open all year -- and it's less crowded in spring than in the high-season summer months. The less-accessible North Rim reopens May 15. Entrance fees are $30 a vehicle, $25 for a motorcycle, and $15 to enter on foot.
GREAT SAND DUNES NATIONAL PARK, COLORADO
There's a lot more to the Great Sand Dunes National Park than endless miles of sand. The park also features aspen forests, tundra, alpine lakes, and wetlands. There are plenty of hiking and backpacking options, and the park even offers dunes-accessible wheelchairs for exploring the sands, which are less dangerously hot in spring. Fees are $15 for a vehicle, $10 for motorcycles, and $7 a person for visitors in an oversize vehicle capable of carrying more than 15 people.
GREAT SMOKY MOUNTAINS NATIONAL PARK
As America's most visited national park, Great Smoky Mountains National Park (which is located in Tennessee and North Carolina) has lots of breathtaking hikes, including the popular 8-mile round-trip Charlies Bunion hike on the Appalachian Trail. Spring means fewer crowds, but check before visiting, as some trails are closed due to recent fire and storm damage. There are no entrance fees to this park, which straddles Tennessee and North Carolina.
HOT SPRINGS NATIONAL PARK, ARKANSAS
The hot springs in this park are the central attraction, but that's not to take away from its 26 miles of trails. Some of the trails date back as far as the 1890s. The longest and most challenging is the 10-mile Sunset Trail, which provides overlooks of the town of Hot Springs and a walk through forests on Sugarloaf Mountain and Fordyce Mountain. There's no entrance fee for this park, which is open year-round.
HUECO TANKS STATE PARK AND HISTORIC SITE, TEXAS
Hueco Tanks is a state park offering camping, rock climbing, picnicking, hiking, and bird-watching. The park also offers guided tours of its pictographs and petroglyphs. Call to make a reservation to hike the self-guided area, as only 70 people are permitted daily. Temperatures are mild in spring and warm up dramatically in summer. There's a $7 entrance fee for adults.
JOSHUA TREE NATIONAL PARK, CALIFORNIA
For visitors who like clambering over boulders and wending their way through desert trails but don't like blistering heat, spring is an optimal time to visit Joshua Tree National Park. It sits at the confluence of two desert ecosystems (the Mojave and the Colorado) and includes everything from short walks and nature trails to challenging hikes that are best undertaken in cooler weather.
LASSEN VOLCANIC NATIONAL PARK, CALIFORNIA
There are more than 150 miles of trails in Lassen Volcanic National Park. Some take hikers past stark reminders of the power of this volcano (especially the accessible trail at the Devastated Area). Spring temperatures are warm but reasonable. Getting into the park costs $20 for a car, $15 for a motorcycle, and $10 for an individual.
MOJAVE DESERT NATIONAL PRESERVE, CALIFORNIA
Another desert spot that is better to hike in spring than summer is the Mojave Desert National Preserve. Springtime brings carpets of colorful wildflowers and moderate temperatures. Noteworthy Mojave trails include the Teutonia Peak Trail (which claims to feature the world's largest and densest Joshua tree forest) and the Barber Peak Loop Trail. There is no entrance fee.
MOUNT RAINIER NATIONAL PARK, WASHINGTON
With a peak that sits at 14,410 feet above sea level, Mount Rainier can carry snow well into spring, but this less-busy season also allows a leisurely visit. Mount Rainier started accepting reservations for wilderness permits March 15, and both the Longmire Museum and the Henry M. Jackson Memorial Visitor Center at Paradise are open in the spring. Entrance fees are $25 for a single vehicle, $10 for an individual, and $20 for a motorcycle.
MOUNT ST. HELENS RECREATION AREA, WASHINGTON
The 1980 eruption of Mount St. Helens permanently changed the mountain, and now visitors can see the impact of the volcano and explore the trails through ash, new growth, and up to the crater itself. There are many more permits available in spring than in summer, when they often sell out shortly after they're made available for purchase for $22 a person.
PETRIFIED FOREST NATIONAL PARK, ARIZONA
Petrified Forest has recently opened new backcountry areas, such as Martha's Butte and Red Basin, to hiking. Spring means cooler temperatures than in the arid summer months, better for clambering over dry, desert landscapes. Seven-day passes are $20 for a vehicle and $10 for individuals and motorcycles.
PETROGLYPH NATIONAL MONUMENT, NEW MEXICO
Petroglyph National Monument encourages hikers to walk more slowly and carefully than they might elsewhere, as there are so many petroglyphs to spot from major trails. Visitors in early spring can also spend less time looking for rattlesnakes, which come out in hot weather. There is no entrance fee, although parking is $1 on weekdays and $2 on weekends.
RED ROCK STATE PARK, ARIZONA
Arizona's Red Rock State Park has a 5-mile trail network of interconnecting loops and several equestrian and biking trails best enjoyed in mild spring temperatures. To get a great vantage point, take the Eagle's Nest Loop for an elevation gain of more than 300 feet. There's a $7 park entrance fee for adults and $4 for children over the age of 6.
REDWOOD NATIONAL PARK, CALIFORNIA
At Redwood National and State Parks, see the remarkable, long-living trees in areas such as Tall Trees Grove. Winter rains begin to lessen in spring, and temperatures are cool, if clammy. Be aware that some trails -- notably the Redwood Creek and Trestle Trails -- may still be closed. This national park is free.
RIO GRANDE NATURE CENTER STATE PARK, NEW MEXICO
Consider one of the weekend bird walks -- or nature walks -- at Rio Grande. The park sits on 270 acres of farmland, meadows, and woods and has an array of turtles, toads, birds, and butterflies to see, some of which are active in springtime. Entry to this park is $3 a vehicle.
SAGUARO NATIONAL PARK, ARIZONA
Named for the iconic cacti the dominate the park's landscape, Saguaro National Park offers camping year-round for $8. Plan ahead, as permits are first come, first served, and springtime's mild temperatures are the main flowering season for annual plants. There's a vast 165-mile network of hiking trails within the park, and weeklong entrance fees are $15 for a vehicle, $10 for a motorcycle, and $5 for an individual.
SHENANDOAH NATIONAL PARK, VIRGINIA
Shenandoah National Park boasts 500 miles of trails for hiking, and 101 are on the storied Appalachian Trail. While springtime weather can be unpredictable, the wildflower displays make up for any sudden showers or cold snaps -- but check the park website for alerts before heading out. Entry is $25 for a vehicle, $20 for a motorcycle, and $10 for individuals.
TORREY PINES STATE NATURAL RESERVE, CALIFORNIA
This San Diego park has 1,500 acres of land studded with chaparral, Torrey pines, clean beaches, and even a lagoon that draws migrating seabirds. Entry is free, but parking rates range from $3 to $20. Free nearby street parking is easier to find in spring, when the reserve is less crowded than in summer.
WALNUT CANYON NATIONAL MONUMENT, ARIZONA
Just outside Flagstaff, this park includes a canyon rim trail through a ponderosa forest with two canyon overlooks, a pueblo set back from the canyon room, and a pit house. There's also the longer Island Trail, which provides more local history. It's windy in the park year-round, but visitors who go in spring avoid the extreme heat and heavy rains of summer and most of the winter snowfall. The entrance fee is $7 a person for a weeklong pass.
YELLOWSTONE NATIONAL PARK
Billed as the world's first national park, Yellowstone (which, though mostly in Wyoming, also reaches into Montana and Idaho) has everything from mountains, forests, and lakes to mudpots, geysers, and hot springs. Backcountry camping and hiking is an option (with a backcountry permit). While springtime weather can be hard to predict, those who go now can bypass the flood of visitors who arrive in summer. The seven-day entrance fee is $30 for a vehicle, $25 for a motorcycle, and $15 for an individual.
YOSEMITE NATIONAL PARK, CALIFORNIA
One of the country's best-known parks, Yosemite National Park has no fewer than 13 campgrounds. Some take reservations and others are operated on a first-come, first-served basis. Entrance fees for a week are $30 for a vehicle, $20 for a motorcycle, and $15 for an individual. Seventy-five percent of the park's visitors come May through October, so spring is a great time to skip the crowds -- and see the park's waterfalls at their best.
ZION NATIONAL PARK, UTAH
Zion has three campgrounds, although one of them, Watchman Campground, has recently been undergoing some construction work; check availability online before going. Springtime can be rainy, but temperatures are rarely as toasty as they are in summer. Seven-day entrances fees are $30 for a vehicle, $25 for a motorcycle, and $15 for an individual.