Winter is a season for planning. How better to pass some of those long, cold, snowy nights than before the fire or at the kitchen table with guidebooks and maps, calculators and checklists? And if you’re thinking of tackling one of the country’s long-distance hiking trails, planning is definitely not over-rated. You need to not only come up with a gear list, but factor in food drops or caches, obtain permits in some cases, and it probably wouldn't hurt to settle on a work-out program to get in shape before you hit the trail.

Here’s a look at some of the long-distance trails that pass through parts of the National Park System, and what planning assistance is out there.

The Appalachian National Scenic Trail

This is the daddy of them all. The prototypical long-distance trail, the AT falls and rises, bends and turns, and meanders 2,175 miles from Mount Katahdin in Maine to Springer Mountain in Georgia. Along the way north to south or south to north you’ll pass through urban areas, areas that still bear vestiges of wilderness, and some 260 huts or lean-tos spaced about a day's walk apart. The beauty of this and the other long-distance trails is you can sample sections of the trail, or do the whole thing in one fell swoop, although going end-to-end would require an understanding employer or a trust fund to alleviate the need to be gainfully employed.

Growing up in New Jersey, I was able to hike sections of the trail in New Jersey and Pennsylvania, though not far as many miles as I would have liked. One four-day, 80-mile jaunt took me through the Delaware Water Gap National Recreation Area and included a night spent near the audibly named "Rice Krispies Spring." While some sections took me through dense forests, others were on ridgelines that offered views down into some of the towns that line the trail's route.

So popular is this trail with folks who have done either the entire walk or simply bite-sized portions that there’s a website dedicated to them -- the Appalachian Long Distance Hikers Association. Check out this group, as it offers some great resources, such as the Appalachian Trail Thru-Hikers’ Companion. This book, small enough to stash in your pack, provides a rundown of “details on shelters, water sources, post offices, hostels, campgrounds, lodging, groceries, restaurants, outfitters, and other related services along the Trail."

In addition, the Companion offers information of historical significance about places you pass through while hiking the A.T. Unlike commercial guides, this book benefits from the latest information from volunteers "who measure, maintain, and manage the Trail and those who hike it regularly.” Among the handy information is a list of post offices and mail drops along the trail, as well as hostels, campgrounds, and showers when you feel the need to take a break from hiking.

Now, you can simply download this book from the group’s website, but help them out by buying a copy.

Another great site is maintained by the Appalachian Trail Conservancy. Visit it and you’ll find all kinds of materials to help plan your end-to-ender. Stuff such as maps of the trail broken down by state, more guidebooks, the “Appalachian Trail Food Planner,” which contains not only recipes but food-drop schedules. There’s even a “how-to” DVD with tips on how to pull off an end-to-end hike, and a page that provides details on how to reach trailheads by bus or train.

Hike the AT end to end and you'll pass through Great Smoky Mountains National Park, the Blue Ridge Parkway, Shenandoah National Park, and the Delaware Water Gap National Recreation Area. And, of course, the AT also is overseen by the National Park Service, though the aforementioned Conservancy is responsible for protecting and promoting the trail.

Handy websites:

http://www.appalachiantrail.com/ -- A resource site for AT hikers.

http://whiteblaze.net/ -- A forum for trail hikers.

http://www.nps.gov/appa/index.htm -- The NPS website to the Appalachian National Scenic Trail.

http://www.outdoors.org/ -- The Appalachian Mountain Club.

Park units crossed:

Delaware Water Gap National Recreation Area

Shenandoah National Park

Blue Ridge Parkway

Great Smoky Mountains National Park

Pacific Crest National Scenic Trail

Running from Mexico to Canada, this trail is younger, but more demanding, than the Appalachian Trail. Passing through six of North America’s seven ecozones, the trail travels 2,650 miles from end to end. Along the way you cross both deserts and peaks rising above 14,000 feet.

Hike the entire route and you'll enjoy a nice sampler of national parks, as you'll walk through portions of Mount Rainier National Park, Crater Lake National Park, Lassen Volcanic National Park, Yosemite National Park, Devils Postpile National Monument, Kings Canyon National Park, and Sequoia National Park.

While 500-600 hikers on average go end-to-end on the AT every year, the Pacific Crest Trail is, you might say, more discerning, or intimidating, or demanding, as only about 300 folks even try to walk every step along the way in one outing, according to the Pacific Crest Trail Association. You can pretty much find one-stop planning at the Pacific Crest Trail Association’s website, as it has materials ranging from what you need to do to enter Canada if you don’t want to stop at the border and foot-care techniques to trip calculators and labels for your resupply boxes.

If you think you want to set off from Mexico to Canada, definitely visit the site’s Permit page, as you’ll need to obtain permits for some national forests, state parks, and, of course, national parks. The site also lists “mentors,” folks who have hiked end-to-end at least once and can offer you advice or answer your questions.

And, if you really want to trim your load, check out this article on long-distance hiker Rod Johnson, who pared his pack weight down to a relatively negligible 9 pounds.

Park units crossed:

Sequoia National Park

Yosemite National Park

Crater Lake National Park

Mount Rainier National Park

North Cascades National Park

Kings Canyon National Park

Devils Postpile National Monument

Lassen Volcanic National Park

Continental Divide National Scenic Trail

This, perhaps, is the most challenging of the long-distance trails for a couple of reasons. First of all, it roams 3,100 miles from the Canadian border down to Mexico. If you managed a 17-mile-a-day pace, it would take you six months to cover that distance. But don’t expect to average so many miles a day. Not every section is completed, so it could take some route-finding at times.

Indeed, according to the Continental Divide Trail Alliance only about 71 percent of the envisioned trail is in place and usable these days. “However, many of those miles are in desperate need of repair, rerouting for scenic, environmental or cultural reasons, or removed from roads and motorized trails,” adds the group.

“Although America’s most challenging trail is not complete, with good maps, a compass and thorough planning, a person can travel from Mexico to Canada following close to the geographic Continental Divide. Signs and markings identifying the CDT vary,” the alliance notes on its website. “Some segments are on well-marked trail, while others require cross-country travel or lead to unclear, poorly marked and unmaintained trails. In some areas, the Trail temporarily follows roads to avoid trespassing on private lands or until a better, non-motorized route is built.”

Since there are sections that aren’t well-defined, it’s recommended that you not only carry map and compass, but know how to use them. Snow travel also is likely, so consider adding an ice axe to your equipment list. Unlike the thorough trip-planning information available for the AT and PCT, you’re largely on your own for juggling the logistics for this 3,100-mile trek.

“If you are planning a long trek on the CDT, you may need to develop a mail drop schedule for resupplying your food rations and other supplies. Many people who plan long distance trips on the CDT are capable of carrying and are required to carry enough food and water for one week. Remember to always have a little extra in case of an emergency,” notes the CDTA. “Mail drop schedules are used to send other essential supplies, such as new hiking boots, replacement parts for stoves or water filters, socks, ice axe, snowshoes and special treats to be eaten during your trail break. It is a good idea to contact your mail drop locations prior to finalizing your schedule in case they are no longer in business or have decided not to accept general delivery packages.”

National parks along the way? Glacier, Yellowstone, Rocky Mountain, and El Malpais National Monument.

Bottom line: If you plan to bite off this baby, visit the alliance’s website and soak in as much information as is available there.

Other, possibly handy, sites:

http://www.cdtsociety.org/ - The Continental Divide Trail Society, which works to both blaze and maintain sections of the trail.

http://www.spiriteaglehome.com/cdt.html -- A site that doesn't seem to be updated regularly, but which nevertheless has some interesting information on the trail.

Park units crossed:

Glacier National Park

Yellowstone National Park

Rocky Mountain National Park

El Malpais National Monument

Wonderland Trail

Unlike the aforementioned trails, the Wonderland does not crisscross a wide variety of public lands. No, this 93-mile loop trail circles Mount Rainier National Park like a wedding ring. It's a classic among Pacific Northwest hikers for the incredible landscape it circles and the elevational gains and drops it forces you to endure. Some days you have to climb up 3,000 feet in elevation, a trek that isn't as easy as you might think if you're carrying a 45-to-50-pound backpack.

Plus, recent storms have littered the trail in places with downed timber, and forced detours elsewhere.

While some ultra-marathoners actually have navigated the entire circuit in less than one day, we're thinking it's wiser to spread out the journey and soak up the atmosphere.

According to frequent Traveler reader Tahoma, "Although extremely rugged, Rainier is such a compact park, that the Wonderland circuit shares some characteristics with corridor trips. Spectacular scenery and even wildlife are commonplace, but the vistas sometimes include roads, clearcuts and lights at night, so it's not a pure wilderness experience by any means, even without the crowds."

There are 18 designated campsites that dot the Wonderland Trail, and landing the ones you want can be tricky due to the lottery system they use. And then there's the task of caching food along the route. "Food can either be mailed in advance of the hike, or you may drop it off at the cache location once you arrive in the park. In either case, food must be packaged in a plastic container to keep rodents out of your food supply. Many choose to use a five gallon plastic bucket or a Rubbermaid-like container," says the park.

Tahoma suggests breaking up the trek into segments, with an "R&R" day or two worked into the mix.

"With a start from Fryingpan Creek on the White River Road, one could do the eastern segment as a 2-night shakedown cruise with superb scenic camps at Summerland and Indian Bar. Both have stone emergency shelters and both would be worth layover days. Traveling south to Box Canyon makes Backbone Ridge a descent, rather than a long, waterless climb. At this point, one could spend a couple days at the Paradise Inn on R&R while dayhiking the southern segment(s) near the roads. If backpacking this section, the most scenic camp would be a 1.5 mile sidetrip at Snow Lake."

Beyond that, he points out that, "Logistically and aerobically, the most difficult section is between Mowich Lake and Longmire. Many hikers begin clockwise from Longmire, but it might be better to save the toughest segment for last. Mowich is traditionally the last park road to open and the first to close. Map study hardly prepares one for the numerous stiff climbs and descents, although it's feasible to abort down several connector trails to the Westside road and probably get a ride with the rangers who use it administratively. With a side-trip, a resupply by mountain bike might also be prearranged. Three nights/four days is probably the bare minimum to avoid a 'sufferathon' on the W-SW segment. The most scenic camps are Golden Lakes and Klapatche Park. Both are worth a layover day, as is Devil's Dream camp in the woods just below Indian Henry's Hunting Ground."

For details on how to organize a hike around Rainier, check out the park's Wilderness Camping and Hiking Homepage: http://www.nps.gov/mora/planyourvisit/wilderness-camping-and-hiking.htm

There are many, many more long-distance hikes available that touch on units of the National Park System, and in the months ahead we'll try to touch on them.