Denver, Colorado, United States. Spring, 2002. Planning a national park vacation really isn't rocket science. All it takes is a little patience and persistence, according to Amfac Parks & Resorts, operator of lodging, restaurants, gift shops and activities at national parks throughout the country.

"In previous years, procrastinators couldn't compete with 'plan-ahead' vacationers because there simply weren't enough rooms to meet the demand," said Andrew N. Todd, president and CEO of Amfac Parks & Resorts. "With decreasing visitation in many national parks, last-minute vacation planners have a better chance than ever of finding accommodations that suit their needs and preferences."

* Educate yourself. Know something about your lodging, tour and activity options before you make reservations. Travelers can find out more information about accommodations, special packages, services and activities by visiting one of several web sites. These include: www.amfac.com, www.travelyellowstone.com, ww.grandcanyonlodges.com, www.zionlodge.com, www.brycecanyonlodge.com, www.grandcanyonnorthrim.com, www.furnacecreekresort.com. and www.flamingolodge.com (Everglades). Travelers can also visit the National Park Service (NPS) site at www.nps.gov.

* Be flexible. Because of the varied occupancy patterns, you may have more luck if you can overnight in the park on a Tuesday and Wednesday versus a Thursday or Friday. The following week, the pattern could be reversed. Travelers with flexible itineraries, particularly during the most popular travel months, are more likely to be successful if they can change their itineraries to accommodate vacancies.

* Be persistent. Because some people book their rooms way in advance and then have to cancel, room availability is constantly changing. If rooms are not available the first time you call the Amfac reservations center, try again another day.

* Be patient and polite. Reservations agents handle many calls each day, so you may have to wait a few moments for an available agent. Also, realize room rates are set by the National Park Service, not the concessioners. The NPS sets rates using a model of comparability, so rates inside national parks are similar to comparable rooms, meals, gifts, etc. outside the park. Room rates for a given year are sometimes not set for several months into that year, so reservations agents may have to tell callers that rates are subject to change.

* Be timely. Even if a lodge has been sold out for months, travelers can sometimes secure rooms when room blocks held by tour wholesalers open up 21 or 30 days in advance.

* Don't believe everything you read or hear. Myths of overcrowding and crumbling facilities abound. Savvy travelers know, however, that visitation is down or flat at many popular parks and the infusion of funds from entrance fees has allowed the National Park Service to launch a variety of improvement projects. Many parks are in better shape than they have been in years.

* Book a tour too. Most parks offer a wide variety of tours and activities, yet many travelers limit their experiences to a handful of stops at park turnoff points. Seeing parks by mule or horse or taking a guided motorcoach tour provides visitors with a better appreciation of a park's offerings. Note to editors: Amfac Parks & Resorts operates lodges, restaurants and other concessions at national and state parks and resorts throughout the country.

Committed to the preservation and protection of the environment in each location, Amfac has implemented a variety of proactive environmental stewardship programs and was the recipient of the 2001 Department of Interior Environmental Achievement Award and Travel Industry Association's Odyssey Award for its environmental initiatives.

Amfac operates concessions in the following locations: Yellowstone National Park, the North and South Rims of Grand Canyon National Park, Bryce Canyon National Park, Zion National Park, Death Valley National Park, Petrified Forest National Park, Everglades National Park, and Mount Rushmore National Memorial; and at resorts in Napa, Calif.; Nebraska City, Neb., Saratoga Springs, N.Y. and seven Ohio State Parks.

For more information about Amfac and links to individual properties, visit: www.amfac.com. For reservations and more information about Grand Canyon, Bryce or Zion, call (1) 303-297-2757. For reservations and more information about Yellowstone, call (1) 307-344-7311. For reservations and more information about Flamingo Lodge in Everglades National Park, call (1) 800-600-3813 or (1) 941-695-3101. For reservations and more information about Ohio State Park Resorts, call (1) 800-282-7275.