The I. B. Perrine Bridge spans the Snake River Canyon on the north side of Twin Falls, carrying US Highway 93 286 metres above the canyon floor. Built in 1976, it was at the time of construction one of the highest bridges in the United States. Even if you have no interest in jumping off it, the bridge is worth stopping for — the canyon views from the pedestrian walkway on the east side are dramatic, and looking down at the river far below gives a sense of the geological scale that irrigation agriculture and a modest city have simply set up camp beside.
The BASE jumping scene attracts serious jumpers from around the world, who treat the bridge as a reliable year-round training ground. On weekends you may see multiple jumps in an afternoon. Watching from the canyon floor — accessible via the Centennial Waterfront Park — gives a different perspective, looking up at jumpers trailing their chutes against the basalt walls. The park itself has pleasant walking trails along the river.