Trailblazers have a new tool at their disposal this summer — and it's much more high-tech than leaving breadcrumbs behind to find their way.

For outdoor enthusiasts, guidebooks and printed maps — essential tools for tracking unknown territory — can be cumbersome to lug around, hard to obtain and grow outdated faster than milk.

But thanks to a variety of Web sites, up-to-date trail maps and descriptions, as well as endless routes and adventures for trekkers to try, are all available with just a few clicks of the mouse.

Now travelers only have to tote a few printouts or download the information onto a PDA and carry it along with their sleeping bags and granola bars.

Check out these sites before you head to the great outdoors: Working exclusively with guidebook publishers, this site offers information and maps on 30,000 trails across the country. For a $30 annual subscription, hikers, bikers and paddlers can download or print out 10 chapters of any book on the site as well as an unlimited number of topographical trail maps per year.

“Instead of purchasing several guidebooks for different activities in different locations, this site gives users the information of 1,000 guidebooks in one spot," said Rob Holmes, director of sales and marketing. "It’s a planning resource. We are a one-stop shop." also delivers weather forecasts for trails and guidebook information that hits their site before bookstores' shelves.

“We actually get guidebooks before they go out to retail stores," Holmes said. "The publisher sends us the digital file, so a lot of times books are launched with us before they go to stores. ... Our site changes daily with new activities and new content.”

National Park Service ParkNet: From Grand Teton National Park (search) in Moose, Wyo., to Padre Island National Seashore (search) near Corpus Christi, Texas, this site has the essential information on all of America's great national parks, which encompass approximately 83.6 million acres of land, according to the site.

The Interactive Map Center offers maps for geographic reference, as well as navigation to and within all national parks. Within the interactive section, functions such as the Park Locator and the Park Atlas give users the ability to navigate any national park and view details such as rivers and lakes and U.S. state boundary lines.

The Web site also provides printable travel guides for each park with vital information such as e-mail addresses, phone numbers and weather and travel updates. Each park's home page also has news and event information such as when baby sea turtles will hatch on the beaches of Padre Island.

Appalachian Trail Conference: The famous trail spans 14 different states from Maine to Georgia — but this online guide breaks it down into five easily manageable segments: Northern New England, Southern New England, Mid-Atlantic, the Virginias and Southern Appalachians.

Within each section, detailed information on weather conditions, the best time of year to hike, sights that can be seen on the trail and the degree of difficulty of each hike can be found. For example, the trail spans 281.4 miles in Maine alone and the best time to hike there is during July and August. The site also warns users about bad times to travel there. "In May and sometimes June, snow still lingers; in June black flies torment hikers and waterlogged trails are muddy and easily damaged.”

If solo hiking isn't your thing, click on the Trail Club link to find Web links to hiking clubs in the area, and make friends with fellow trekkers. GORP's Trail Finder provides information on 6,000 different trails. After a quick registration, users can click on a U.S. map anywhere they fancy taking a hike and find out difficulty levels, trail highlights and a quick description of what lies in store for them on their travels.

The search engine helps hikers find trails by keywords quickly, and insider information is posted, such as this one for the Arroyo Seco (search) trail near Los Angeles: "You enter the road to the right [east] by riding around a locked yellow gate. Immediately, you will see a JPL ONLY sign. Ignore it; it should be on the other road."

And the "amount of use" rating can filter out trails that are more popular with people than nature. The Arroyo is classified as having "heavy" use, so those seeking a path less-trodden can choose one of the other 24 Angeles National Forest (search) trails listed.