(CNN) -- Get off the grid and into the wild on an overnight backpacking trip.
Backpackers are likely to experience the wilderness much more intimately than other types of travelers -- and reap the benefits of physical exercise and mental refreshment at the same time.
"A variety of studies show that even relatively brief experiences in nature can enhance feelings of energy and vitality," said Dr. Richard M. Ryan, professor of psychology, psychiatry and education at the University of Rochester.
Nature has a way of magnifying little details you may have overlooked, and your safety and overall enjoyment depend on your preparedness. So if you're not sure where to begin your backpacking adventure, consider a guided trip.
Trip outfitters will often supply you with all the gear you need, including food. And guided getaways are not just for beginners. Seasoned backpackers often opt for guided trips too, says Ian Elman, owner of Southern Yosemite Mountain Guides, a company that specializes in these types of excursions.
Many guides will customize trips to suit your specific needs and physical condition. Guided trip costs can range from less than $200 per person to thousands of dollars depending on the nature and length of your trip. Starting locally is a great way to gauge your interest and skill level for future expeditions.
Ready for some adventure? These five immense U.S. national parks offer backpacking trips of a lifetime:
Grand Canyon National Park
The Grand Canyon in Arizona offers some of the most challenging backpacking in the United States due to its steep trails and fast-changing weather conditions. If you opt to hike from the North Rim to the South Rim, you'll experience an elevation differential of more than 10,000 feet from start to finish, according to the National Park Service. The reward? Getting a unique perspective on the natural wonder and its geological rainbow from the base of the canyon.
A popular itinerary for first-time backpackers is to spend a few nights at either Bright Angel or Indian Garden Campgrounds. These sites can be accessed by the Bright Angel Trail, and you'll need a park service backcountry permit.
The National Park Service maintains a list of companies authorized to guide backpackers within the park.
Glacier National Park
Glacier National Park in Montana ranks as one of the most popular backpacking parks, according to the National Park Service. Its alpine lakes, steep mountains, abundant wildlife and more than 700 miles of trails make this park a backpacker's dream.
Belly River Trail is a popular route. This 13.6 mile trail offers spectacular mountainous scenery and passes by campgrounds at Elizabeth Lake and Helen Lake. The trail drops 740 feet in the first few miles then levels out. Backcountry campers will need a permit.
Glacier Guides is the park-service approved outfit for guided and custom backpacking trips into the park's backcountry.
Yellowstone National Park
Yellowstone is one of the most diverse national parks, with landscapes ranging from forested mountain slopes to valleys bustling with wildlife to roaring rivers.
Some 1,000 miles of trails criss-cross the park, some offering easy trips over gentle terrain, while others require technical skills and endurance.
The park service says many of Yellowstone's trails are more than 7,000 feet above sea level and most areas have snow until late May or early June. The park service suggests avoiding high elevations early in the season because some of these areas may be closed if conditions are considered unsafe for visitors.
A list of outfitters permitted to guide backpackers within Yellowstone can be viewed on the park's official website.
Denali National Park and Preserve
Denali, in Alaska's interior, encompasses more than 6 million acres of land and is home to North America's tallest peak at 20,320 feet -- Mount McKinley. Black bears and grizzly bears are among the stars for wildlife spotters (just keep your distance).
This national park is about the size of Vermont, yet only a handful of trails exist in this vast, solitary area. Most of the trails are within three miles of the park entrance, but if you're adventurous, you can explore the wild terrain, which ranges from a low-elevation taiga forest to snow-covered mountains. You'll need to get a backcountry permit in person before you set out.
North Cascades National Park
Escape to this national park in Washington state and surround yourself with mountains, glaciers and streams. Grizzly bears are among the 75 mammal species that inhabit the wilderness.
Backpacking is popular at North Cascades and trips can range from an overnight on relatively level land to multiday hikes over multiple mountain passes. Mountaineering treks for varying skill levels are an option, too, but this is not a beginner's venture.
Beaver Loop trail is a moderate, forested route. The 34.2 mile journey offers a side trip with views of Challenger glacier and peak and usually takes three to four days.
The park service lists authorized guides for North Cascades backpacking on its site.