The National Park Service has come a long way in the past 25 or 30 years in making the parks more accessible for visitors with disabilities. Most parks have accessible restrooms, and many have at least one trail that is wheelchair accessible -- the Rim Trail at Bryce Canyon is a prime example. Several parks with sandy conditions, such as Great Sand Dunes, offer free use of specially designed wheelchairs with balloon tires for travel over sand.

In addition, as campgrounds, boat docks, and other facilities are upgraded, improvements are being made to make them more accessible. Many parks now have campsites designed specifically for travelers in wheelchairs, most in-park lodging offers accessible rooms -- some with roll-in showers -- and park amphitheaters can usually accommodate wheelchair users.

But perhaps just as important as upgrades in facilities is the prevailing attitude of National Park Service personnel that these parks are for the public -- the entire public -- and they are going to do whatever it takes to help everyone enjoy his or her park experience. People with special needs are encouraged to talk with park workers, who can usually assist, opening locked gates to get vehicles closer to scenic attractions, or simply by pointing out trails with the lowest grades or with portable toilets that are accessible.

One note on service dogs: Seeing Eye and other service dogs are not considered pets and are legally permitted anywhere in the parks. However, because of potential problems with wildlife or terrain (sharp rocks on some trails can cut dogs' paws), it's best for people taking service dogs into the parks to discuss their plans with rangers beforehand.

Many of the major car-rental companies now offer hand-controlled cars for drivers with disabilities and can provide those vehicles with advance notice. Wheelchair Getaways (tel. 800/642-2042; www.wheelchairgetaways.com) rents and sells specialized vans with wheelchair lifts and other features for visitors with disabilities. It has outlets in most western states.

And don't forget your National Parks and Federal Recreational Lands Pass. It is free and will grant you free admission to most national parks and a 50% discount on many park services and facilities.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.