The Extended Tour

Closest entrance and distance: 5 miles from the Gardiner (north) entrance

This area might offer the best argument for getting off the roads, out of your car, and into the environment. Although it's possible to see most of the wildlife and the major thermal areas from behind car windows, your experience of the park will be multiplied tenfold through the expenditure of a small amount of energy. Most people in average shape are capable of negotiating the trails here, a significant percentage of which are level or only moderately inclined boardwalks. Even the more challenging trails frequently have rest areas where you can catch your breath or, more important, stop and absorb the magnificent views.

One of Yellowstone's most unique, beautiful, and fascinating areas is the Upper and Lower terraces. Strolling among them, you can observe Mother Nature going about the business of mixing and matching heat, water, limestone, and rock fractures to sculpt the area. This is one of the most colorful areas in the park; its tapestries of orange, pink, yellow, green, and brown, formed by masses of bacteria and algae, seem to change colors before your eyes.

The mineral-rich hot waters that flow to the surface here do so at an unusually constant rate, roughly 750,000 gallons per day, depositing almost 2 tons of limestone every 24 hours. Contours are constantly changing in the hot springs as formations are shaped by large quantities of flowing water, the slope of the ground, and trees and rocks that determine the direction of the flow.

On the flip side of the equation, nature has a way of playing tricks on some of her creatures: Poison Spring is a sinkhole on the trail, so named because carbon dioxide collects there, often killing creatures that stop for a drink.

The Lower Terrace Interpretive Trail is one of the best ways to see this area. The trail starts at 6,280 feet and climbs another 300 feet along rather steep grades through a bare, rocky, thermal region to a flat alpine area and observation deck at the top. A park guide says that the 1.5-mile round-trip walk to the Upper Terrace and back normally takes 2 hours, but it can be done in less time.

Liberty Cap is a 37-foot-tall dome at the entrance to the interpretive trail. Once the site of a percolating hot spring, the domed Cap deposit is the result of 2,500 years of continuous gushing. The Hayden Expedition named it as such because of its resemblance to hats worn by Colonial patriots during the French Revolution.

After passing Palette Spring, where bacteria create a collage of browns, greens, and oranges, you're on your way to Cleopatra and Minerva terraces. Minerva is a favorite of visitors because of its bright colors and travertine formations, the product of limestone deposits. In nature's way, these attractions occasionally become unruly and spray water and mineral deposits large enough to bury the boardwalk.

The hike up the last 150 feet to the Upper Terrace Loop Drive is slightly steeper, although there are benches at frequent intervals. From here you can see all the terraces and several springs -- Canary Spring and New Blue Spring being the most distinctive -- and the red-roof buildings of Fort Yellowstone, which is now the park headquarters.

Near Fort Yellowstone is the large Albright Visitor Center (tel. 307/344-2263), which has more visitor information and publications than other centers, along with significant exhibits telling the story of the park from prehistory through the creation of the National Park Service. It's open daily from 8am to 7pm during peak season. Enclosed in floor-to-ceiling glass cases are uniforms, furniture, side arms, and memorabilia that reflect the park's varied human history. There are excellent photography exhibits, with much of the work by the first park photographer, William Henry Jackson. A second level is filled with displays of the wildlife that inhabits the park, including wolves, mountain lions, waterfowl, and other birds. Films on the park's origin and the art that it has inspired are shown throughout the day.

You can continue walking along Upper Terrace Loop Drive, which is also accessible by car. The Upper Terrace has its own unique attractions, including New Highland Terrace, which is a forest of tree skeletons engulfed by travertine, and Angel Terrace, known for its pure white formations.

Just steps from the lower terrace is the trail head for the Beaver Ponds Loop Trail, a 5-mile round-trip jaunt through fir and spruce, then sagebrush and aspen, along a trail that follows Clematis Gulch. The ponds are about 2.5 miles from the trail head, after a moderate elevation gain, where the resident toothy engineers are most active early in the morning and at night. The area is also a hangout for elk and bears, and can be closed early in the summer season.