From wikepedia: Yosemite Falls is the highest measured waterfall in North America. Located in Yosemite National Park in the Sierra Nevada mountains of California, it is a major attraction in the park, especially in late spring when the water flow is at its peak.
The total 2425-foot (739-m) distance from the top of the upper falls to the base of the lower falls qualifies Yosemite Falls as the 6th highest waterfall in the world (with the recent discovery of Gocta Cataracts it presently appears on some lists as the seventh). Although often referred to as a "two-stage drop", the falls actually consist of three sections:
The 1430-foot (425-m) plunge qualifies the Upper Falls alone as one of
the twenty highest waterfalls in the world. Trails up from the valley
floor and down from other regions of the park outside the valley
proper lead to both the top and base of Upper Yosemite Falls. The
upper fall is formed by the swift waters of Yosemite Creek, which,
after meandering through Eagle Creek Meadow, hurl themselves over the
edge of a hanging valley in a spectacular and deafening show of force.
Between the two obvious main plunges there are a series of cascades and smaller plunges generally referred to as "the cascades". Taken together these account for another drop of 675 feet (205 m), more than twice the height of the Lower Falls. Because of the layout of the area, the lack of any major drops in this section and the lack of public access, they are often overlooked. Most viewpoints in the valley miss them entirely. Several vantage points for the cascades are found along the Yosemite Falls trail. Several hikers climbing down from the trail towards the cascades have required an expensive helicopter rescue due to steep and slippery terrain and features.
The final 320-foot (97-m) drop of the Lower Falls, adjacent to an accessible viewing area, provides the most-used viewing point for the waterfalls. Yosemite Creek emerges from the base of the Lower Falls and flows into the Merced River nearby. Like many areas of Yosemite the plunge pool at the base of the Lower Falls is surrounded by dangerous jumbles of talus made even more treacherous by the high humidity and resulting slippery surfaces.