FOR BUDGET-MINDED adventurers planning their vacation, America s 391 national parks and historical sites are a big draw. Roughly 275 million visitors a year trek to such natural wonders as the Grand Canyon or landmarks like the Statue of Liberty. Unfortunately, their popularity is a double-edged sword, as the wear and tear caused by

so many visitors leads to increased maintenance requirements and costs.

Keeping these sites in top condition is the job of the National Park Service, a bureau of the Department of the Interior. But the sheer number it s responsible for, coupled with long-term underfunding, has left a $9 billion backlog of maintenance projects. This year s operating budget of $2.13 billion plus $920 million in stimulus money will help. But the creation of new parks and sites only compounds the problem, says Jeff Ruch, executive director of the Public Employees for Environmental Responsibility. In the past 20 years, the number has grown by 13 percent, to 391. And don t ask the Park Service to pick and choose. All the parks and sites are equally important, says Park Service spokesperson David Barna, since they contribute to what defines us as Americans.

WHEN SUE RUDDY, a 56-year-old teacher in Michigan, grew tired of the annual summer trip to Florida, she and her husband decided to take a tour of national parks, with stops in Grand Teton, Zion and Yellowstone, to visit the geographical marvels of the U.S., she says. Visitors to national parks generally come in one of two varieties: Some are like Ruddy, who wants to experience the parks undisturbed by the outside world, while others come seeking different forms of recreation. That creates some conflicts, Barna says, particularly around the issue of noise. The original Park Service mandate which he says is to preserve and protect these sites unimpaired and allow for recreational use wasn t designed to account for today s idea of recreation, including motorboats, fully equipped RVs and ubiquitous cell phones.

One solution would be to split things up. Already, designated recreation parks, like Lake Mead in Nevada, offer outdoor fun that ranges from swimming to Jet Skiing. Meanwhile, wilderness parks, like Olympic National Park and Yosemite National Park, are great for visitors who just want to commune with nature.

OF ALL THE SITES maintained by the Park Service, more than half are historical or cultural, such as Alcatraz Island in San Francisco or Abraham Lincoln s birthplace in Kentucky. But because of the lack of money for the upkeep of these places, many may not be preserved for future generations. The National Parks Conservation Association, a parks advocacy group, recently did a survey of the condition of sites, measuring the deterioration of historic buildings and artifacts, and overall, gave them a failing grade, says Ron Tipton, the organization s senior VP of policy, who oversaw the study. It shows that the long-term condition is seriously threatened, he says.

For example, the monuments and memorials at Gettysburg marking major battle sites are declining yearly, and there s no guarantee they ll be around in 20 years, says Tipton. The main problem is lack of funds, without which it s hard for the Park Service managers to address those challenges, says Mike Cipra, the California Desert program manager at the National Parks Conservation Association. Supporters can make a donation at NationalParks.org or via the donation boxes located in national park sites.

THE NO. 1 CAUSE of fatalities in Death Valley National Park is single-vehicle car accidents, of which there are typically three to six a year, says Terry Baldino, spokesperson for the park. That s very high, he says. So you might assume that maintaining the park s heavily used roads would be at the top of the Park Service to-do list. But the main thoroughfare in Death Valley still has a very dangerous 13-mile stretch, says Cipra the shoulders are narrow, there s barely room for cars to pass each other, and the pavement is chipping away. It seems basic that roads in the park should at least be drivable, Cipra says.

Indeed, the past few years have seen a lot of sexy ribbon-cutting things, says Barna. But that s largely because of the Centennial Challenge, a 10-year, $3 billion fund-raising plan to match donations from private parties to build new features inside parks, like visitor centers, rather than tackle the long list of maintenance issues which in turn creates additional maintenance requirements for these new features. It s a real problem, says Barna. We neglect to take into account the future operating costs of these facilities, and that s part of the burden.

IN THE LATE 1990s the number of annual visitors to national parks peaked at over 285 million, then fell off after 9/11, bottoming out at 266 million in 2003. But in recent years, attendance has bounced back. Not surprisingly, the most popular parks are leading the way, seeing some of the biggest increases in attendance numbers: Last year the Grand Canyon had 4.4 million visitors, a 7 percent increase from 2003, and Zion National Park accommodated 2.7 million people, a 9 percent increase from 2003. Unfortunately, that s not necessarily good news for visitors. The popular parks are getting loved to death, says Ruch.

Trying to visit the south rim of the Grand Canyon in July, for example, could leave you searching for parking for over an hour, says Tipton. Try the north rim instead, says Deborah Trevino, an Illinois-based travel agent. It s a lot less crowded, and you don t have to take a shuttle bus. Another good way to avoid the tourist swarm is to get out of your car and explore on foot; most visitors stay close to main thoroughfares or parking areas when visiting national parks. Ask at the visitor center for advice on getting a little further off the beaten path.

6. They re not called the Great Smokies for nothing.

HIKING IN THE Smoky Mountains this summer could leave you out of breath and it may have little to do with fitness. The Great Smokies are in one of the most polluted national parks; on some days the ozone and particle levels are on par with New York or L.A. Wind currents bring in pollutants from Knoxville, Tenn., and Ohio, which, due to the orientation of the mountains, get trapped in the park. In fact, on 37 days last summer, warnings were issued that the air quality was too poor for, say, a vigorous hike, according to the conservation association. Visitors to Shenandoah in Virginia used to be able to see the Washington Monument, over 80 miles away, from points on the park s Skyline Drive. But today you might not be able to see a single mile.

Under the Clean Air Act of 1977, the Environmental Protection Agency was supposed to prevent significant deterioration of air quality in national parks. But it s complex, says Tipton, since the two main causes are cars and coal plants. The EPA says it has responded to the problem with its Regional Haze Program, which calls for state and federal government to work together in improving visibility conditions in the parks by 2064.

ONE ONGOING issue for national parks is the lack of rangers. National Park rangers who serve as both security staff and as tour guides are generally considered to be among the best in the world. But during

peak season, during the months of July and August, national parks routinely rely on volunteers to serve as tour guides, since due to budget constraints, they often can t hire enough rangers to accommodate the large crowds. That means getting a good guide often becomes a crap shoot at best, says Tipton.

The good news is that the Park Service is planning to add 3,000 seasonal rangers this year. But even so, you still have another option at many locations: Visitors can download an audio or video podcast to their smartphone. Don t have one? At Shenandoah you can rent a GPS Ranger loaded up with park information. Not all the parks offer such units yet, but there are plans in the works to use technology to improve the visitor experience across the board.

IF YOU REALLY want to rough it, build your own campfire, cook your own food and sleep under the stars, then a National Park s backcountry is where you want to be. Entrance fees to some of the most popular parks range anywhere from $5 to $25 a carload, which is supposed to give you access to the entire park. But those fees don t necessarily cover hiking and camping in the backcountry, the part of the park that hasn t been developed for visitors. To do that you need a permit, which can cost up to $25, and you may face extra charges for every night you spend there.

Before the 1990s, all backcountry permits were free. They were used to cap the number of visitors in those areas at any one time, in order to limit the impact on the natural environment. But free or not, these passes remain in high demand; you generally need to apply for one at least three months in advance. To do so, contact the park s visitor center.

IF YOU WANT TO go mountain biking in the wilderness of a national park, your options might seem pretty limited. You generally have to stick to the few parks such as Canyon Lands National Park in Utah that have designated mountain-biking paths. But there might be more paths on the way: Nearly 8 million acres of backcountry all across the U.S. could eventually be opened to mountain bikes, depending on a proposed review of a 20-year-old regulation that made it difficult for parks to implement that change. If such a change were made, trails that are currently open to hikers and horseback riders could also be open to mountain bikers a move hiking and riding advocates say could be dangerous. Besides the extra wear mountain bikes would leave on the trails, the mere sight of an off-road Lance Armstrong could readily startle a horse.

One alternative for mountain bikers who don t want to wait is to visit those national forests that allow unlimited mountain biking on their trails. Visitors to Grand Teton National Park, for example, can also hit the Bridger-Teton National Forest right next door for unlimited mountain biking on all its trails. In Bridger-Teton you ll find 4.4 million acres, roughly twice the size of Yellowstone, where mountain bikers can ride on any trail they like.

ONCE YOU VE MADE your decision to visit a national park, you re going to need to figure out where to stay. If you have your eye on one of the iconic lodges right inside a national park, be ready to pay luxury prices, anywhere from $150 to $600 a night, for what most people wouldn t necessarily call luxury, says travel agent Trevino. Jenny Lake Lodge in the Grand Teton National Park, for example, costs $585 a night for a room for two. What do you get for that kind of money? Complimentary breakfast, a five-course dinner and the use of horses. What s more surprising is what you often don t get there s no television, no radio and no Wi-Fi access in many of these lodges.

So regardless of which park you re in, be prepared to go rustic. Most of the lodges are very basic, Trevino says. You might get lucky and have a TV in some. Looking for a more modern accompaniment to your nature gazing? Try checking out the hotels near, but not inside, the national parks. They re generally 10 to 15 percent cheaper than on-site lodging. To find a list of places to stay both in and around the parks, go to www.nps.gov, search for the park you plan to visit, then click on Plan My Trip. You ll also find information there on making camping reservations.