Falls Creek begins at Dorothy Lake, which is located at one of the northernmost points in the national park. The headwaters, at nearly in elevation, lie between Forsyth Peak, Dorothy Lake Pass, Bond Pass and Bigelow Peak. It plunges into Jack Main Canyon, paralleling the Pacific Crest Trail, which carries it south to round Chittenden Peak, where Tilden Creek enters from the left. From there the creek passes Branigan Lake, then cascades down into the basin containing Lake Vernon, which it empties into. Issuing out of the southwest end of the lake, the creek flows in a southwesterly direction, approaching Hetch Hetchy Reservoir. Very near the mouth, it runs past Hetch Hetchy Dome and splits into two distributaries, which both cascade over the rim of Hetch Hetchy Valley, forming two waterfalls, Wapama Falls and Tueeulala Falls, near Hetch Hetchy Dome.