A sierra is a chain of mountains with sharp, jagged peaks that look like the teeth of a saw. The word comes from Spanish, where sierra literally means “saw,” the tool with pointed teeth used for cutting wood.

When Spanish explorers first saw certain mountain ranges in the Americas, the peaks reminded them of a saw blade cutting into the sky. Today, many mountain ranges carry sierra in their name, like California's Sierra Nevada or Mexico's Sierra Madre. You'll find sierras throughout Spanish-speaking countries and in places those explorers once traveled.

The Sierra Nevada contains some of America's most dramatic landscapes, including Yosemite National Park with its towering granite cliffs. John Muir, the famous naturalist, spent years exploring these mountains and wrote about their beauty to help convince the government to protect them.

When you see a mountain range called a sierra, picture that distinctive profile: not smooth, rounded hills, but sharp peaks and ridges that really do look like someone dragged a saw's edge across the horizon.