America’s first and most famous national park, Yellowstone is the primary regional destination. Travelers often take a cursory tour of the park in a single day, but try to set aside a minimum of three days to discover this diverse and geologically fascinating place.

If you have only a day or two, pick a couple of spots and see them right. Don’t just check out the views everyone else sees; find a nearby trail and do a little exploring on your own.

It would be easy to spend a full week in Yellowstone, plus another week in nearby Grand Teton National Park and Jackson Hole. Before visiting, contact Yellowstone (307/344-7381, www.nps.gov/yell) for a copy of the park newspaper and other information.

The vast majority of Yellowstone visitors come June-August; anyone arriving at other times may find closed facilities and campgrounds, along with minimal Park Service staffing. Campgrounds that remain open year-round are often surprisingly busy since travelers have limited options.

To avoid surprises, it’s wise to make camping reservations well ahead of your trip, even in the off-season. The upside for off-season travelers is an abundance of wildlife and the lack of crowds.

For geyser action, check out the Norris Geyser Basin, home to Steamboat Geyser, which blasts 300 feet into the air on its extremely rare eruptions. Old Faithful is the most famous of dozens of geysers, hot springs, and other geothermal features that fill Upper Geyser Basin, the largest concentration of geysers in the world.

The equally acclaimed Old Faithful Inn is a delightful century-old log structure. Stay for a meal or a night, or just step inside to soak up the ambience. Five miles north of Old Faithful, take time to visit Midway Geyser Basin with its massive Grand Prismatic Spring, the park’s largest hot spring.

Mammoth Hot Springs, home to park headquarters and a small, interesting museum, is famous for its ever-changing palette of softly colored springs. The bucolic northeast corner is a good place to see bison, elk, and wolves, and nearby Tower Fall provides a great photo op.

The park’s most spectacular feature may be the Grand Canyon of the Yellowstone, with the river plummeting 308 feet over Lower Falls. South of here is Hayden Valley (look for bison, elk, and occasional bears), along with the belching geysers and hot springs of Mud Volcano, and Yellowstone Lake, the largest high-elevation lake in North America. On its north shore is the picturesque and graceful Lake Yellowstone Hotel.