Pinnacle
A pinnacle is a freestanding pillar of rock that looks like a needle trying to pierce the sky. Pinnacles form because weathering and erosion wears the rock down to a sharp, jagged point.
Flatiron
Flatirons look like giant, stone ironing boards. They have a flat slab on one side and a steep overhanging face on the other. Flatirons are formed because slow-motion force over time (like continents pushing together) pushes the rock up from the earth.
Butte
The distinguishing feature of a butte is its flat top---some are large enough on top to throw a football across. Sheer cliffs flank the sides of buttes, making them look like giant fortresses that dominate the desert floor. Buttes form because the hard rock at the summit avoids erosion and the softer underlying rock gets eroded over time. A butte with more than 11,000 sq. ft. on its top is called a mesa.
Article Written By Rob Holzman
Based in the Pacific Northwest, Rob Holzman has been writing outdoor articles since 1997. He recently published the first comprehensive rock climbing guidebook for Pennsylvania and has fiction work published in the "Pacific Northwest Inlander". Holzman has also appeared on FOX television and has been an outdoor consultant for the Discovery Channel.