Yosemite Valley, California
At a majestic 2,425ft, Yosemite Falls is the highest waterfall in North America, and the fifth tallest on the planet (the tallest is Venezuela's Angel Falls, at 3,212ft). Technically three waterfalls in one (Upper Yosemite Fall, the Middle Cascades, and Lower Yosemite Fall), YF is active from November through July and approximately 2,400 gallons of melted snow/water rush over it per second.
Pro tip: Prefer see what you're getting into before you arrive? Watch the waterfall's webcam, right here.