Upper Yosemite Fall, Spring - Yosemite National Park, CA.. The Spring thaw brings large amounts of water to the fall making its beauty all the more awe-inspiring. The Upper Fall portion drops 1,430 feet. The waterfalls of Yosemite reach their peak in May or June.Yosemite Falls - Yosemite Creek spills over the rim of the Yosemite Valley walls to form Yosemite Falls. The creek and falls are a tributary of the Merced River which winds its way through Yosemite Valley.Photo: Russ Finley Film Size 4X5