Yellowstone National Park

A pool's color is often determined by what grows in it. Brightly colored algae and bacteria thrive in the hot springs. Each color indicates a specific temperature range :

- green and brown = cooler water.

- oranges and yellows = hotter water.

West Thumb Geyser Basin (general view)

Sunset Lake on Black Sand Basin.

Bisons live 12 to 15 years. They are the largest land mammals in North America. Their hump is a large muscle that helps them to hold up their huge head. Males (bulls) commonly weigh 2,000 pounds (900 kg). Females (cows) are smaller, averaging 1,000 pounds (450 kg). Calves are born in April and May, and weigh 25 to 40 pounds (11 to 18 kg) at birth.

Elks at Mammoth Hot Springs (Terraces in the background)

Grand Canyon of the Yellow...stone !

Yellow mineral patches on the canyon walls indicate hot spring and fissures. Even a minor tremor can trigger a landslide from thermally weakened cliffs. Stream vents and geysers are still at work on the canyon wall.

Return to http://mahaut.fr/ - Updated 18 oct. 2008