A massive mudslide that has authorities searching for three missing men in remote western Colorado highlights the dangers of heavy rain saturating slopes.

Half a mile of a rain-soaked ridge near the small mountain town of Collbran, Colorado, collapsed Sunday, sending a mudslide careening down Grand Mesa, one of the world's largest flat-topped mountains. The slide was three to four miles (five to six kilometers) long and a two miles across, according to news reports, making it considerably larger than the mudslide that struck Oso, Washington, in March.

"It's an understatement to say that it is massive," Sheriff Stan Hilkey told CNN. "The power behind it was remarkable."

Rescue workers are searching for Clancy Nichols, 51; his son Danny, 24;