Base jumping requires jumping off a perfectly sound structure.

Northwest Backroads

BASE is an acronym for building, antennae, span and earth.

Spanning across the Snake River in Twin Falls, Idaho, is the Perrine Bridge, a place where rookies and pros alike come to experience a thrill of a lifetime.

At 486 feet above the Snake River, the bridge is the only manmade structure in the United States where it's legal to base-jump 365 days a year.

Click on the video to watch the action.