One of several gorgeous landscapes near the Midway Geyser Basin at Yellowstone National Park.

Yellowstone Bubbles Up with Surreal Color, Beauty

WEST YELLOWSTONE, Wyo. — From across the Yellowstone terrain, you can see them- hissing, belching, filling the air with strange odors. No, we're not talking about the tourists (nearly three million visit annually). Yellowstone National Park contains the most extraordinary display of hydro- and geo-thermal activity in the world: exploding geysers, bubbling mud pots, and steamy thermal pools. It's an inspiring, at times smelly and even exhilarating sight.

The southwest side of the park near Old Faithful between Madison and West Thumb Village is a study in contrast: the tranquil forest mingles with thundering steam vents and thermal exhaust plumes — evidence of the earth's churning heat below. Beneath the flora and fauna lies a scorching pressure buildup, enough to catapult water to heights of 185 feet. Much of Yellowstone sits on an underground dome of super-hot magma, just three miles below ground. Ground water trickles down thousands of feet where its heated by molten rock and rises back at temperatures of 400 degrees Fahrenheit.

The forces that shaped Yellowstone over a thousand centuries have yielded a fascinating landscape of surreal beauty. We were most impressed by the Lower and Midway Geyser Basins, where the boardwalks and trails take you around to multiple geysers, mud pots and thermal pools. The sights along some of the boardwalk stretches are eerily other-worldly. Superheated water laced with acids, minerals and micro-organisms sluice over the basin surface, creating exotic hues — orange and aquamarine, emerald and chocolate brown — colors reminiscent of the surface of Mars or the moons of Jupiter.

Geyser eruptions happen regularly, throughout the day and night. The grand-daddy draw of them all, Old Faithful, erupts at approximately 90 minute intervals. This Yellowstone highlight is flanked all around by guest lodging (open seasonally), a restaurant, museum, gift shop, and visitor center, all of which accommodate the flow of tourism. In most cases, these geothermal features are a short walk from your car. Every so often, nature reaches out to you. Be prepared to stop for wildlife crossing the park roads.

Insider tip: The Yellowstone Road Report (307) 344-2117 is good to have in the late fall and winter months. The automated hotline is updated daily, sometimes hourly, with information on road conditions, construction, and closings, which are vital in planning your trip.

• Established in 1870, Yellowstone is the oldest, and largest national park, covering 2.2 million acres.
• Elevations: Lowest, 5,282 feet at Reese Creek; Highest, 11,358 feet at Eagle Peak.
• More than 1,000 species of flowering plants, and 67 mammal and 320 bird species.
• Hiking: More than 950 miles of backcountry trails. Roads and facilities take up less than 3 percent of the park; the rest is wilderness.
• Mud pots: Micro-organisms convert the stinky hydrogen sulfide gases into sulfuric acid, which breaks solid rock down into clay mud.
• Fumaroles: These "dry geysers" act as steam vents that makes the ground shake and produce a sound like roaring thunder.